Ylide-functionalised phosphanes for use in metal complexes and homogeneous catalysis

ABSTRACT

The invention relates to ylide-functionalized phosphane ligands, the production of same and use in transition metal compounds, as well as the use of same as catalysts in organic reactions.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a national stage application (tinder 35 U.S.C. §371) of PCT/EP2018/071550, filed Aug. 8, 2018, which claims benefit ofGerman Application No. 102017213817.3, filed Aug. 8, 2017, both of whichare incorporated herein by reference in their entirety.

The invention relates to ylide-functionalized phosphane ligands, thepreparation thereof, and the use thereof in transition metal compounds,and the use thereof as catalysts in organic reactions.

Background of the Invention

The synthesis of complex molecules if often a central task in the finechemicals industry, for example, in order to prepare products for theproduction of pharmaceuticals, dyes, agrochemicals, materials, etc.Catalytic processes for functionalization reactions are frequentlyrequired therein, such as coupling reactions (Suzuki, Heck, Sonogashiraetc.) or hydrofunctionalizations (hydroamination, hydrosilylation, etc.)for the derivatization of olefins, aryls, or alkynes. Such catalyses arecritically influenced by the metal and the ligands employed.

Phosphanes are among the most frequently used ligands in catalysis.Adjusting their electronic and steric parameters is critical to increasethe activity of a catalyst, to determine selectivities, and to be ableto enlarge the substrate diversity (A. C. Hillier et al.,Organometallics, 22: 4322 (2003); H. Clavier et al. Chem. Commun., 46:841 (2010); Z. L. Niemeyer, A. Milo, D. P. Hickey, M. S. Sigman, NatureChem. 8: 610 (2016); C. A. Tolman, Chem. Rev. 77, 313 (1977); G.Frenking, Organometallics, 28, 3901 (2009)). The variability ofphosphanes and the possibility to manipulate their electronic and stericproperties substantiates the preference of their use as compared to manyother ligand systems. Therefore, phosphanes are employed in a widevariety of reactions, such as palladium-catalyzed coupling reactions (M.A. Wünsche et al., Angew. Chem. Int. Ed., 54, 11857 (2015); D. S. Surryet al., Angew. Chem. Int. Ed., 47, 6338 (2008); R. Martin et al., Acc.Chem. Res., 41, 1461 (2008); S. Kotha et al., Tetrahedron, 58, 9633(2002)), or gold-catalyzed hydroamination reactions (Lavallo, V. et al.;Angew. Chem., Int. Ed., 52, 3172 (2013); E. Mizushima et al., Org.Lett., 5, 3349 (2003); Y. Wang et al., Nature. Commun., 1 (2014)). Novelactive catalyst systems are based on, inter alia,adamantyl-functionalized phosphanes (DE-A-10037961, WO 02/10178, L. Chenet al., J. Am. Chem. Soc., 138, 6392 (2016); C. A. Fleckenstein et al.,Chem. Soc. Rev., 39, 694 (2010); K. A. Agnew-Francis et al., Adv. Synth.Catal., 358, 675 (2016)), or biaryl phosphane ligands (U.S. Pat. No.6,307,087, D. S. Surry et al., Angew. Chem., 120, 6438 (2008); Angew.Chem. Int. Ed., 47, 6338 (2008); R. A. Altman et al., Nat. Protoc., 2,3115 (2007); D. S. Surry et al., Chem. Sci., 2, 27 (2011); E. J. Cho etal., Science, 328, 1679 (2010); D. A. Watson et al., Science, 325, 1661(2009)). A survey of important homogeneous catalyses with phosphaneligands is found, for example, in B. Cornils, W. A. Hermann, AppliedHomogenous Catalysis with Organometallic Compounds, Vol 12, VCH,Weinheim, 1996.

Ligand design is decisive in catalysis to enable reactions, or to beable to direct them into desired directions. Thus, for example, thedevelopment of new phosphane ligands is often required to realize morecost-effective starting substrates (e.g., chlorides instead of iodides),higher catalyst productivities and activities, and a broader substrateand reaction diversity.

SUMMARY OF THE INVENTION

Aspect (1): Phosphane ligands of formulas YPR¹R² (I), Y₂PR¹ (II) and Y₃P(III)

where

Y represents an ylide substituent bound to the phosphorus atom throughthe carbanionic center and having onium groups On and X groups,

On, independently of the onium groups in other ylide substituents, isselected from phosphonium groups —P(R³R⁴R⁵), ammonium groups —N(R³R⁴R⁵),sulfoxonium groups —SOR³R⁴ and sulfonium groups —S(R³R⁴),

X, independently of the X groups in other ylide substituents, isselected from hydrogen, alkyl, aryl, alkenyl and heteroaryl groups thatmay be unsubstituted or substituted with functional groups, silyl(—SiR³R⁴R⁵), sulfonyl (—SO₂R³), phosphoryl (—P(O)R³R⁴, —P(S)R³R⁴,—P(NR³)R⁴R⁵ ₂), cyano (—CN), alkoxy (—OR³) and amino (—NR³R⁴) groups,and

R¹, R², R³, R⁴ and R⁵, if any, are independently selected from alkyl,aryl and heteroaryl groups that may be unsubstituted or substituted withfunctional groups, with the proviso that R¹ and R² are not methyl if Xis hydrogen or trimethylsilyl and Z is trimethylphosphonium, or that R¹and R² are not phenyl if X is p-toluylsulfonyl (—SO₂(p-toluyl)) and Z istriphenylphosphonium.

2. The phosphane ligands according to item 1, wherein

(i) the alkyl groups are selected from linear, branched-chain or cyclicC₁₋₁₀ alkyl groups, preferably from C₁₋₆ alkyl groups orC₄₋₁₀-cycloalkyl groups, the aryl groups are selected from C₆₋₁₄ arylgroups, preferably from C₆₋₁₀ aryl groups, the alkenyl groups areselected from mono- or polyunsaturated linear, branched-chain or cyclicC₂₋₁₀ alkenyl groups, preferably from C₂₋₆ alkenyl groups, and theheteroaryl groups are selected from C₆₋₁₄ heteroaryl groups, preferablyfrom C₆₋₁₀ heteroaryl groups having 1 to 5 heteroatoms selected from N,O and S; and/or

(ii) the functional groups are selected from alkyl (—R¹¹), especiallyC₁₋₆ alkyl groups, C₆₋₁₀ aryl (—R¹²), halogen (-Hal), hydroxy (—OH),cyano (—CN), alkoxy (—OR³), amino (—NR¹¹ ₂, —NHR¹¹, —NH₂), mercapto(—SH, —SR¹¹), wherein R¹¹, independently of further R¹¹ residues, isselected from C₁₋₆ alkyl residues.

3. The phosphane ligands according to item 1 or 2, represented byformula (I) or (II)

wherein On is a phosphonium group —P(R³R⁴R⁵), in which R³, R⁴ and R⁵ areindependently selected from the group consisting of C₁₋₆ alkyl groups,C₄₋₁₀ cycloalkyl groups, C₆₋₁₀ aryl groups, X is selected from the groupconsisting of linear, branched-chain or cyclic C₁₋₆ alkyl groups, C₆₋₁₀aryl groups, mono- or polyunsaturated linear, branched-chain or cyclicC₂₋₆ alkenyl groups, a trialkylsilyl (—SiR³R⁴R⁵), arylsulfonyl(R¹²—SO₂R³) group, and R¹ and R² are C₆₋₁₀ aryl groups or C₁₋₆ alkyl andcycloalkyl groups.

4. The phosphane ligands according to one or more of the precedingitems, wherein R³, R⁴ and R⁵ are independently selected from the groupconsisting of methyl, ethyl, butyl, cyclohexyl, phenyl, and combinationsthereof.

5. The phosphane ligands according to one or more of the precedingitems, wherein R³, R⁴ and R⁵ are the same and are selected from thegroup consisting of methyl, ethyl, butyl, cyclohexyl, phenyl, andcombinations thereof, especially cyclohexyl and phenyl.

6. The phosphane ligands according to one or more of the precedingitems, wherein X is selected from the group consisting of methyl, ethyl,cyclohexyl, phenyl, p-tolyl, trimethylsilyl, p-tolylsulfonyl, orcombinations thereof.

7. The phosphane ligands according to one or more of the precedingitems, wherein R¹ and R² are independently selected from the groupconsisting of phenyl, cyclohexyl, methyl, and combinations thereof.

Aspect (2):

8. A process for preparing the phosphane ligands according to any ofitems 1 to 3, comprising

(a) the reaction of a metallated ylide with a halophosphane, adihalophosphane, or phosphorus trichloride,

(b) the reaction of an ylide-functionalized halophosphane ordihalophosphane with an organometallic reagent,

(c) the phosphanylation of an onium salt, phosphanylation withhalophosphanes in the presence of a base, or

(d) the deprotonation of an α-phosphanyl substituted onium salt with abase.

Aspect (3):

9. Use of the phosphane ligands according to any of items 1 to 3 in thesynthesis of metal complexes or metal salts.

10. The use according to item 9, wherein said metal complexes or metalsalts are precious metal or transition metal complexes or precious metalor transition metal compounds.

11. The use according to item 9 or 10, wherein said metal, preciousmetal or transition metal complexes and salts with the phosphane ligandsaccording to any of items 1 to 7 are employed in homogeneous catalysis.

Aspect (4):

12. Use of the phosphane ligands according to any of items 1 to 7 incombination with metal, precious metal or transition metal complexes ormetal, precious metal or transition metal salts as catalysts, whereinthe ligands are added to the metal, precious metal or transition metalprecursor compounds in situ, or the isolated metal, precious metal ortransition metal complexes of the phosphane ligands according to aspect(3) are employed.

13. The use according to items 9 to 12, wherein the metals platinum,palladium and nickel, preferably palladium, are used.

14. The use according to items 9 to 13, wherein the metals copper,silver and gold, preferably gold, are used.

15. The use according to items 9 to 14, wherein the ligands are employed

(i) in catalytic hydrofunctionalization reactions of alkynes andalkenes;

(ii) in catalytic hydroamination reactions of alkynes and alkenes;

(iii) in catalytic O—H addition reactions to alkynes and alkenes;

(iv) in catalytic coupling reactions;

(v) in catalytic Suzuki coupling reactions, especially for thepreparation of biaryls;

(vi) in catalytic cross-coupling reactions, especially C—N and C—Ocoupling reactions; and/or

(vii) in catalytic Heck coupling reactions, especially for thepreparation of arylated olefins, and Sonogashira coupling reactions,especially for the preparation of arylated and alkenylated alkynes.

Aspect (5):

16. Metal complexes containing a phosphane ligand of formulas YPR¹R²(I), Y₂PR¹ (II) and Y₃P (III)

where

Y represents an ylide substituent bound to the phosphorus atom throughthe carbanionic center and having onium groups On and X groups,

On, independently of the onium groups in other ylide substituents, isselected from phosphonium groups —P(R³R⁴R⁵), ammonium groups —N(R³R⁴R⁵),sulfonium groups —SOR³R⁴ and sulfonium groups —S(R³R⁴),

X, independently of the X groups in other ylide substituents, isselected from hydrogen, alkyl, aryl, alkenyl and heteroaryl groups thatmay be unsubstituted or substituted with functional groups, silyl (—SiR³₃R⁴R⁵), sulfonyl (—SO₂R³), phosphoryl (—P(O)R³R⁴, —P(S)R³R⁴, —P(NR³)R⁴R⁵₂), cyano (—CN), alkoxy (—OR) and amino (—NR²) groups, and

R¹, R², R³, R⁴ and R⁵, if any, are independently selected from alkyl,aryl and heteroaryl groups that may be unsubstituted or substituted withfunctional groups, with the proviso that R¹ and R² are not methyl if Xis hydrogen or trimethylsilyl and Z is trimethylphosphonium, or that Rand R² are not phenyl if X is p-toluylsulfonyl (—SO₂(p-toluyl)) and Z istriphenylphosphonium.

17. The metal complexes according to item 16, wherein (i) the alkylgroups are selected from linear, branched-chain or cyclic C₁₋₁₀ alkylgroups, preferably from C₁₋₆ alkyl groups or C₄₋₁₀-cycloalkyl groups,the aryl groups are selected from C₆₋₁₄ aryl groups, preferably fromC₆₋₁₀ aryl groups, the alkenyl groups are selected from mono- orpolyunsaturated linear, branched-chain or cyclic C₂₋₁₀ alkenyl groups,preferably from C₂₋₆ alkenyl groups, and the heteroaryl groups areselected from C₆₋₁₄ heteroaryl groups, preferably from C₆₋₁₀ heteroarylgroups having 1 to 5 heteroatoms selected from N, O and S; and/or (ii)the functional groups are selected from alkyl (—R¹¹), especially C₁₋₆alkyl groups, C₆₋₁₀ aryl (—R¹²), halogen (-Hal), hydroxy (—OH), cyano(—CN), alkoxy (—OR³), amino (—NR¹¹ ₂, —NHR¹¹, —NH₂), mercapto (—SH,—SR¹¹), wherein R¹¹, independently of further R¹¹ residues, is selectedfrom C₁₋₆ alkyl residues.

18. The metal complexes according to item 16 or 17, having phosphaneligands of formula (I) or (II)

wherein On is a phosphonium group —P(R³R⁴R⁵), in which R³, R⁴ and R⁵ areindependently selected from the group consisting of C₁₋₆ alkyl groups,C₄₋₁₀ cycloalkyl groups, C₆₋₁₀ aryl groups, X is selected from the groupconsisting of linear, branched-chain or cyclic C₁₋₆ alkyl groups, C₆₋₁₀aryl groups, mono- or polyunsaturated linear, branched-chain or cyclicC₂₋₆ alkenyl groups, a trialkylsilyl (—SiR³R⁴R⁵), arylsulfonyl(R¹²—SO₂R³) group, and R¹ and R² are C₆₋₁₀ aryl groups or C₁₋₆ alkyl andcycloalkyl groups.

19. The metal complexes according to one or more of the above items,wherein R³, R⁴ and R⁵ are independently selected from the groupconsisting of methyl, ethyl, butyl, cyclohexyl, phenyl, and combinationsthereof.

20. The metal complexes according to one or more of the preceding items,wherein R³, R⁴ and R⁵ are the same and are selected from the groupconsisting of methyl, ethyl, butyl, cyclohexyl, phenyl, and combinationsthereof, especially cyclohexyl and phenyl.

21. The metal complexes according to one or more of the preceding items,wherein X is selected from the group consisting of methyl, ethyl,cyclohexyl, phenyl, p-tolyl, trimethylsilyl, p-tolylsulfonyl, orcombinations thereof.

22. The metal complexes according to one or more of the preceding items,wherein R¹ and R² are independently selected from the group consistingof phenyl, cyclohexyl, methyl, tert-butyl and combinations thereof.

23. The metal complexes according to items 18 to 22, wherein saidcomplex is a palladium allyl complex having the following structure (V)or (VI):

wherein X is an anion,

Y, R¹, R² are defined as in the preceding items,

R³³, R³⁴ and R³⁵ are independently selected from H, alkyl, aryl andheteroaryl groups that may be unsubstituted or substituted withfunctional groups; or

at least two of R³³, R³⁴ and R³⁵ form a carbocyclic ring with 5 to 14carbon atoms,

Ar represents a substituted or unsubstituted, especially a substituted,aryl group.

24. The metal complexes according to item 23, wherein R³³, R³⁴ and R³¹are independently selected from linear, branched-chain or cyclic C₁₋₁₀alkyl groups, preferably from C₁₋₆ alkyl groups or C₄₋₁₀-cycloalkylgroups, the aryl groups are selected from C₆₋₁₄ aryl groups, preferablyfrom C₆₋₁₀ aryl groups, the alkenyl groups are selected from mono- orpolyunsaturated linear, branched-chain or cyclic C₂₋₁₀ alkenyl groups,preferably from C₂₋₆ alkenyl groups, and the heteroaryl groups areselected from C₆₋₁₄ heteroaryl groups, preferably from C₆₋₁₀ heteroarylgroups having 1 to 5 heteroatoms selected from N, O and S, wherein allof the groups mentioned above may be substituted with functional groups;and/or

at least two of R³³, R³⁴ and R³⁵ form a carbocyclic ring that is a C₄₋₁₀cycloalkyl group, or a C₆₋₁₄ aryl group, which may be substituted withone or more functional groups; and

Ar are selected from C₆₋₁₄ aryl groups, preferably C₆₋₁₀ aryl groups,and the heteroaryl groups are selected from C₆₋₁₄ heteroaryl groups,preferably from C₆₋₁₀ heteroaryl groups having 1 to 5 heteroatomsselected from N, O and S, wherein all of the groups mentioned above maybe substituted with functional groups; and

the functional groups are selected from alkyl (—R¹¹), especially C₁₋₆alkyl groups, C₆₋₁₀ aryl (—R¹²), halogen (-Hal), hydroxy (—OH), cyano(—CN), alkoxy (—OR³), amino (—NR¹¹ ₂, —NHR¹¹, —NH₂), mercapto (—SH,—SR¹¹), wherein R¹¹, independently of further R¹¹ residues, is selectedfrom C₁₋₆ alkyl residues.

25. The metal complexes according to item 23 or 24, wherein X isselected from the group of halogen, tosylate, nosylate and mesylate.

26. The metal complexes according to one or more of the preceding items,wherein X is selected from the group of fluorine, chlorine, bromine,iodine, tosylate, nosylate and mesylate, and/or aryl is selected fromphenyl, m-tolyl, p-tolyl, o-tolyl, mesityl, 1,3-diisopropylphenyl.

27. A process for performing a coupling reaction containing the steps of

-   -   providing a reaction mixture containing at least a substrate,        coupling partner, and a metal complex according to item 16 to        26, or a metal complex containing a ligand according to item 1;        and    -   reacting said substrate with said coupling partner in the        presence of the metal complex or its derivative to form a        coupling product.

28. The process according to item 27, wherein the metal of said metalcomplex is a precious metal and/or a transition metal.

29. The process according to item 27 or 28, wherein the metal of saidmetal complex is a metal of group 10 or 11 of the Periodic Table of theelements.

30. The process according to one or more of items 27 to 29, wherein themetal of said metal complex is selected from the group consisting ofcopper, silver, gold, platinum, palladium, nickel, and combinationsthereof.

31. The process according to one or more of items 27 to 30, wherein thesubstrate is a substituted aromatic compound.

32. The process according to item 31, wherein said substituted aromaticcompound is an aromatic or heteroaromatic compound.

33. The process according to item 31 or 32, wherein said substitutedaromatic compound is substituted with a leaving group, or an unsaturatedaliphatic group, or a leaving group.

34. The process according to item 33, wherein said leaving group isselected from the group consisting of halogen, tosylate, nosylate andmesylate, and/or said unsaturated aliphatic group is selected from thegroup consisting of alkene or alkyne, especially with 2 to 12,especially with 2 to 8, carbon atoms.

35. The process according to one or more of the preceding items, whereinthe coupling partner comprises an organometallic compound.

36. The process according to item 35, wherein said organometalliccompound is selected from the group consisting of organic boroncompounds, organolithium compounds, organozinc compounds, organolithiumcompounds, and Grignard compounds.

37. The process according to item 35 or 36, wherein said organometalliccompound includes at least one aromatic residue.

38. The process according to item 36, wherein said organometalliccompound includes at least one unsaturated aliphatic residue.

39. The process according to item 36, wherein said organometalliccompound includes at least one saturated aliphatic residue.

40. The process according to one or more of items 27 to 39, wherein thecoupling reaction may be selected from the group consisting of

(i) catalytic hydrofunctionalization reactions of alkynes and alkenes;

(ii) catalytic hydroamination reactions of alkynes and alkenes;

(iii) catalytic O—H addition reactions to alkynes and alkenes;

(iv) catalytic coupling reactions;

(v) catalytic Suzuki coupling reactions, especially for the preparationof biaryls;

(vi) catalytic cross-coupling reactions, especially C—N and C—O couplingreactions; and/or

(vii) catalytic Heck coupling reactions, especially for the preparationof arylated olefins, and Sonogashira coupling reactions, especially forthe preparation of arylated and alkenylated alkynes.

41. Use of the metal complexes according to items 16 to 26 inhomogeneous catalysis, advantageously in coupling reactions, which maybe selected from the group consisting of

(i) catalytic hydrofunctionalization reactions of alkynes and alkenes;

(ii) catalytic hydroamination reactions of alkynes and alkenes;

(iii) catalytic O—H addition reactions to alkynes and alkenes;

(iv) catalytic coupling reactions;

(v) catalytic Suzuki coupling reactions, especially for the preparationof biaryls;

(vi) catalytic cross-coupling reactions, especially C—N and C—O couplingreactions; and/or

(vii) catalytic Heck coupling reactions, especially for the preparationof arylated olefins, and Sonogashira coupling reactions, especially forthe preparation of arylated and alkenylated alkynes.

DETAILED DESCRIPTION OF THE INVENTION

It has now been found that the ylide-functionalized phosphane ligands offormulas (I), (II) and (III) having a carbanionic carbon center inα-position to the phosphorus atom as described below and theirtransition metal complexes achieve the above object. Thus, the inventionrelates to:

(1) phosphane ligands of formulas YPRR′ (I), Y₂PR (II) and Y₃P (III)

where

Y represents an ylide substituent bound to the phosphorus atom throughthe carbanionic center and having onium groups On and X groups,

On, independently of the onium groups in other ylide substituents, isselected from phosphonium groups —PRR′₂, ammonium groups —NRR′₂,sulfoxonium groups —SOR₂ and sulfonium groups —SRR′,

X, independently of the X groups in other ylide substituents, isselected from hydrogen, alkyl, aryl, alkenyl and heteroaryl groups thatmay be unsubstituted or substituted with functional groups, silyl(—SiR₃), sulfonyl (—SO₂R), phosphoryl (—P(O)R₂, —P(S)R₂, —P(NR)R₂),cyano (—CN), alkoxy (—OR) and amino groups (—NR₂),

and

R and R′, if any, are independently selected from alkyl, aryl andheteroaryl groups that may be unsubstituted or substituted withfunctional groups;

(2) a process for preparing the phosphane ligands according to aspect(1), comprising

(a) the reaction of a metallated ylide with a halophosphane, adihalophosphane, or phosphorus trichloride,

(b) the reaction of an ylide-functionalized halophosphane ordihalophosphane with an organometallic reagent,

(c) the phosphanylation of an onium salt, phosphanylation withhalophosphanes in the presence of a base, or

(d) the deprotonation of an α-phosphanyl substituted onium salt with abase;

(3) the use of the phosphane ligands according to aspect (1) in thesynthesis of transition metal complexes or transition metal salts; and

(4) the use of the phosphane ligands according to aspect (1) incombination with transition metal complexes or transition metal salts ascatalysts, wherein the ligands are added to the transition metalprecursor compounds in situ, or the isolated transition metal complexesof the phosphane ligands obtainable according to aspect (3) areemployed.

Aspect (1) of the invention provides phosphane ligands of formulas YPRR′(I), Y₂PR (II) and Y₃P (III).

In the formula, R and R′ represent alkyl, aryl and heteroaromaticresidues with and without further functional groups (e.g., amines,ethers).

“On” describes a substituent with a positive charge, such as oniumgroups, mainly phosphonium groups —PRR′₂, ammonium —NRR′₂, sulfoxoniumgroups —SOR₂, or sulfonium groups —SRR′. The carbon atom directly boundto the phosphorus atom formally bears a negative charge.

X symbolizes alkyl, aryl or alkenyl groups both with and without furtherfunctional groups, heteroaromatics, as well as hydrogen or functionalgroups, such as silyl, sulfonyl (—SO₂R with R=alkyl, aryl), phosphoryl(—P(O)R₂, —P(S)R₂, —P(NR)R₂), —CN, alkoxy (—OR), amino (—NR₂), whereinthe residue R always includes alkyl and aryl residues.

Preferably, the alkyl groups are selected from linear, branched-chain orcyclic C₁₋₁₀ alkyl groups, preferably from C₁₋₆ alkyl groups, the arylgroups are selected from C₆₋₁₄ aryl groups, preferably from C₆₋₁₀ arylgroups, the alkenyl groups are selected from mono- or polyunsaturatedlinear, branched-chain or cyclic C₂₋₁₀ alkenyl groups, preferably fromC₂₋₆ alkenyl groups, and the heteroaryl groups are selected from C₄₋₁₄heteroaryl groups, preferably from C₆₋₁₀ heteroaryl groups having 1 to 5heteroatoms selected from B, N, O and S. It is further preferred thatthe functional groups are selected from alkyl (—R″), perfluoroalkyl(—C_(x)F_(2x+1), with x=1 to 6, such as —CF₃, —C₂F₅ etc.), halogen(-Hal), hydroxy (—OH), cyano (—CN), alkoxy (—OR″), carbonyl (—CO₂H,—CO₂R″, —COR″, —CONHR″), amino (—NR″₂, —NHR″, —NH₂), amido (—NHCOR″,—NHSO₂R″), mercapto (—SH, —SR″), sulfonyl (—SO₃H, —SO₂R″), phosphorus(—PR″₃, —P(O)R″₂, —P(S)R″₂, —P(NR)R″₂), silyl (—SiR″₃) and nitro groups,wherein R″, independently of further R″ residues, is selected from C₁₋₆alkyl and C₆₋₁₄ aryl residues.

In addition to the simple ylide substitution, the phosphanes may also bedoubly and triply ylide-substituted to obtain phosphanes of formulas(II) Y₂PR and (III) Y₃P. A preferred embodiment of aspect (1) arephosphane ligands of formula (I)

where On is a triarylphosphonium group, especially atriphenylphosphonium group, X is a trialkylsilyl, cyano (—CN), methyl orarylsulfonyl group, especially a trimethylsilyl or p-tolylsulfonylgroup, and R and R′ are aryl or alkyl groups, especially phenyl,cyclohexyl or methyl groups.

Aspect (2) of this invention relates to the preparation of theylide-functionalized phosphane ligands according to the invention. Theycan be prepared via two alternative synthetic pathways, which allows fora broad variation of the substitution pattern: The synthesis can beachieved either through an α-metallated ylide, which is reacted with acorresponding chlorophosphane (route A), or through the α-deprotonationof an α-phosphanyl-substituted phosphonium salt (route B).

Route A: The α-metallated ylides required for route A can be prepared bythe deprotonation of classical ylides with metal bases, such asorganolithium compounds or alkali metal amides (T. Scherpf et al.,Angew. Chem. Int. Ed., 54, 8542 (2015); Bestmann, H. J. et al.; Angew.Chem. Int. Ed., 26, 79 (1987)). The reaction thereof withchlorophosphanes of the type RR′PCl (R, R′=alkyl, aryl residues) yieldsthe ylide-functionalized phosphane on a direct route. When phosphorustrichloride is used, ylide-functionalized chlorophosphanes of the typeYPCl₂ can also be prepared, which can be reacted in a further step withorganometallic reagents (or organolithium, organomagnesium andorganozinc reagents) to form an alkyl/aryl phosphane. Reactions ofchlorophosphanes with metal bases are described, for example, inHouben-Weyl, Methoden der organischen Chemie, 1963, volume XII, 1 S33.The use of phosphorus trichloride and dichlorophosphanes also enablesaccess to multiply ylide-substituted phosphanes.

Route B: Preparation method B is a practical alternative to route A,which circumvents the isolation of sensitive metallated intermediates.Proceeding from a classical onium salts, the introduction of thephosphane moiety is effected by using a halophosphane in the presence ofa base. When an excess of base is used, the formation of theylide-functionalized phosphane is achieved on a direct route. Thus, thismethod allows for the preparation of the ligands from readily availablestarting substances or from commercially available precursors.

The novel phosphanes are reacted with transition metal compounds to formthe corresponding complexes, such as with compounds of the metals Ni,Pd, Pt, Rh, Ir, Cu and Au. The complexes can be either isolated assolids, or generated in situ and used further for catalyticapplications. In the complexes, the phosphane ligands prove to be verystrong donor ligands whose donor capabilities exceeds that of classicalphosphane ligands. This could be demonstrated by means of the Tolmanparameter (TEP), i.e., by means of infrared spectroscopy anddetermination of the CO stretching vibration in the correspondingRh(acac)(CO)L complexes (with L=phosphane ligand, andacac=acetylacetonato) (C. A. Tolman, Chem. Rev. 77, 313 (1977)).

The transition metal complexes of the ylide-functionalized phosphaneligands are employed in different homogeneously catalyzed reactions,such as in palladium-catalyzed coupling reactions (e.g., C—C—, C—O, C—Ncouplings), and gold-catalyzed hydroamination reactions. In thesereactions, they exhibit extraordinarily high activities that exceedthose of analogous complexes with common phosphane ligands. Thus, in thegold-catalyzed hydroamination of alkynes, high conversion rates areobserved already at room temperature. In part, TONs of more than 10,000are achieved. Analogous reactions with other phosphane ligands usuallyrequire higher reaction temperatures of further additions of additives(D. Malhotra et al., Angew. Chem. Int. Ed., 53, 4456 (2014); E.Mizushima et al., Org. Lett., 5, 3349 (2003)). In addition, the systemsin part proved to be extremely robust towards water and atmosphericoxygen, so that catalyses could be performed also without taking furtherprecautionary protective measures. This applies, for example, to theautocatalyzed hydroamination of phenylacetylene, which did not show anydecrease in catalytic activity even in the presence of water. In thecase of the palladium-catalyzed coupling and cross-coupling reactions,comparably mild reaction conditions could be applied, and even couplingsof aryl chlorides could be realized. For example, in the case of C—Ncoupling reactions, high conversion rates even with difficult substratescould be achieved already at room temperature.

Therefore, the invention relates to phosphane ligands of formulas YPR¹R²(I), Y₂PR¹ (II) and Y₃P (III)

where

Y represents an ylide substituent bound to the phosphorus atom throughthe carbanionic center and having onium groups On and X groups,

On, independently of the onium groups in other ylide substituents, isselected from phosphonium groups —P(R³R⁴R⁵), ammonium groups —N(R³R⁴R⁵),sulfoxonium groups —SOR³R⁴ and sulfonium groups —S(R³R⁴),

X, independently of the X groups in other ylide substituents, isselected from hydrogen, alkyl, aryl, alkenyl and heteroaryl groups thatmay be unsubstituted or substituted with functional groups, silyl(—SiR³R⁴R⁵), sulfonyl (—SO₂R³), phosphoryl (—P(O)R³R⁴, —P(S)R³R⁴,—P(NR³)R⁴R⁵ ₂), cyano (—CN), alkoxy (—OR³) and amino (—NR³R⁴) groups,and

R¹, R², R³, R⁴ and R⁵, if any, are independently selected from alkyl,aryl and heteroaryl groups that may be unsubstituted or substituted withfunctional groups;

especially with the proviso that R¹ and R² are not methyl if X ishydrogen or trimethylsilyl and Z is trimethylphosphonium, or that R¹ andR² are not phenyl if X is p-toluylsulfonyl (—SO₂(p-toluyl)) and Z istriphenylphosphonium.

In these ligands:

(i) the alkyl groups are selected from linear, branched-chain or cyclicC₁₋₁₀ alkyl groups, preferably from C₁₋₆ alkyl groups, the aryl groupsare selected from C₆₋₁₄ aryl groups, preferably from C₆₋₁₀ aryl groups,the alkenyl groups are selected from mono- or polyunsaturated linear,branched-chain or cyclic C₂₋₁₀ alkenyl groups, preferably from C₂₋₆alkenyl groups, and the heteroaryl groups are selected from C₆₋₁₄heteroaryl groups, preferably from C₆₋₁₀ heteroaryl groups having 1 to 5heteroatoms selected from B, N, O and S, and/or

(ii) the functional groups are selected from alkyl (—R¹), perfluoroalkyl(—C_(x)F_(2x+1), with x=1 to 6, such as —CF₃, —C₂F₅ etc.), halogen(-Hal), hydroxy (—OH), cyano (—CN), alkoxy (—OR″), carbonyl (—CO₂H,—CO₂R″, —COR″, —CONHR″), amino (—NR″₂, —NHR″, —NH₂), amido (—NHCOR″,—NHSO₂R″), mercapto (—SH, —SR″), sulfonyl (—SO₃H, —SO₂R″), phosphorus(—PR″₃, —P(O)R″₂, —P(S)R″₂, —P(NR)R′₂), silyl (—SiR″₃) and nitro groups,wherein R″, independently of further R″ residues, is selected from C₁₋₆alkyl and C₆₋₁₄ aryl residues.

A specific embodiment relates to phosphane ligands represented byformula (I) or (II)

wherein On is a phosphonium group —P(R³R⁴R⁵), in which R³, R⁴ and R⁵ areindependently selected from the group consisting of C₁₋₆ alkyl groups,C₄₋₁₀ cycloalkyl groups, C₆₋₁₀ aryl groups, X is selected from the groupconsisting of linear, branched-chain or cyclic C₁₋₆ alkyl groups, C₆₋₁₀aryl groups, mono- or polyunsaturated linear, branched-chain or cyclicC₂₋₆ alkenyl groups, a trialkylsilyl (—SiR³R⁴R⁵), arylsulfonyl(R¹²—SO₂R³) group, and R and R² are C₆₋₁₀ aryl groups or C₁₋₆ alkyl andcycloalkyl groups.

R³, R⁴ and R⁵ may be independently selected from the group consisting ofmethyl, ethyl, butyl, cyclohexyl, phenyl, and combinations thereof. R³,R⁴ and R⁵ may be the same and selected from the group consisting ofmethyl, ethyl, butyl, cyclohexyl, phenyl, and combinations thereof,especially cyclohexyl and phenyl.

X may be selected from the group consisting of methyl, ethyl,cyclohexyl, phenyl, p-tolyl, trimethylsilyl, p-tolylsulfonyl, orcombinations thereof.

R¹ and R² may be independently selected from the group consisting ofphenyl, cyclohexyl, methyl, and combinations thereof.

Another embodiment relates to a process for preparing the phosphaneligands, comprising

(a) the reaction of a metallated ylide with a halophosphane, adihalophosphane, or phosphorus trichloride,

(b) the reaction of an ylide-functionalized halophosphane ordihalophosphane with an organometallic reagent,

(c) the phosphanylation of an onium salt with halophosphanes in thepresence of a base, or

(d) the deprotonation of an α-phosphanyl substituted onium salt with abase.

The phosphane ligands may be used in the synthesis of metal complexes ormetal salts.

In particular, these may be precious metal or transition metal complexesor precious metal or transition metal compounds. In particular, metalsof group 10 or 11 of the Periodic Table of the elements may be employed.

The metal, precious metal or transition metal complexes and salts withthe phosphane ligands as described above may be employed in homogeneouscatalysis.

In particular, the phosphane ligands according to aspect (3) may beemployed in combination with metal, precious metal or transition metalcomplexes or metal, precious metal or transition metal salts ascatalysts, wherein the ligands are added to the metal, precious metal ortransition metal precursor compounds in situ, or the isolated metal,precious metal or transition metal complexes of the phosphane ligandsaccording to aspect (3) may be employed in the synthesis of transitionmetal complexes or transition metal salts.

In one embodiment, the metals platinum, palladium and nickel, preferablypalladium, may be used.

In another embodiment, the metals copper, silver and gold, preferablygold, may be used.

In the above uses, the ligands may be employed

(i) in catalytic hydrofunctionalization reactions of alkynes andalkenes;

(ii) in catalytic hydroamination reactions of alkynes and alkenes;

(iii) in catalytic O—H addition reactions to alkynes and alkenes;

(iv) in catalytic coupling reactions;

(v) in catalytic Suzuki coupling reactions, especially for thepreparation of biaryls;

(vi) in catalytic cross-coupling reactions, especially C—N and C—Ocoupling reactions; and/or

(vii) in catalytic Heck coupling reactions, especially for thepreparation of arylated olefins, and Sonogashira coupling reactions,especially for the preparation of arylated and alkenylated alkynes.

In particular, the patent application further relates to metal complexescontaining a phosphane ligand of formulas YPR¹R² (I), Y₂PR′ (II) and Y₃P(III)

where

Y represents an ylide substituent bound to the phosphorus atom throughthe carbanionic center and having onium groups On and X groups,

On, independently of the onium groups in other ylide substituents, isselected from phosphonium groups —P(R³R⁴R⁵), ammonium groups —N(R³R⁴R⁵),sulfoxonium groups —SOR³R⁴ and sulfonium groups —S(R³R⁴),

X, independently of the X groups in other ylide substituents, isselected from hydrogen, alkyl, aryl, alkenyl and heteroaryl groups thatmay be unsubstituted or substituted with functional groups, silyl (—SiR³₃R⁴R⁵), sulfonyl (—SO₂R³), phosphoryl (—P(O)R³R⁴, —P(S)R³R⁴, —P(NR³)R⁴R⁵₂), cyano (—CN), alkoxy (—OR³) and amino (—NR³R⁴) groups, and

R¹, R², R³, R⁴ and R⁵, if any, are independently selected from alkyl,aryl and heteroaryl groups that may be unsubstituted or substituted withfunctional groups, with the proviso that R¹ and R² are not methyl if Xis hydrogen or trimethylsilyl and Z is trimethylphosphonium, or that R¹and R² are not phenyl if X is p-toluylsulfonyl (—SO₂(p-toluyl)) and Z istriphenylphosphonium.

The alkyl groups may be selected from linear, branched-chain or cyclicC₁₋₁₀ alkyl groups, preferably from C₁₋₆ alkyl groups orC₄₋₁₀-cycloalkyl groups, the aryl groups are selected from C₆₋₁₄ arylgroups, preferably from C₆₋₁₀ aryl groups, the alkenyl groups areselected from mono- or polyunsaturated linear, branched-chain or cyclicC₂₋₁₀ alkenyl groups, preferably from C₂₋₆ alkenyl groups, and theheteroaryl groups are selected from C₆₋₁₄ heteroaryl groups, preferablyfrom C₆₋₁₀ heteroaryl groups having 1 to 5 heteroatoms selected from N,O and S; and/or

(ii) the functional groups are selected from alkyl (—R¹¹), especiallyC₁₋₆ alkyl groups, C₆₋₁₀ aryl (—R¹²), halogen (-Hal), hydroxy (—OH),cyano (—CN), alkoxy (—OR³), amino (—NR¹¹ ₂, —NHR¹¹, —NH₂), mercapto(—SH, —SR¹¹), wherein R¹¹, independently of further R¹¹ residues, isselected from C₁₋₆ alkyl residues.

The metal complexes may be, in particular, precious metal or transitionmetal complexes or precious metal or transition metal compounds. Inparticular, metals of group 10 or 11 of the Periodic Table of Elementsmay be employed.

In one embodiment, the metals platinum, palladium and nickel, preferablypalladium, may be used.

In another embodiment, the metals copper, silver and gold, preferablygold, may be used.

Advantageously, these may be metal complexes having phosphane ligands offormula (I) or (II)

wherein On is a phosphonium group —P(R³R⁴R⁵), in which R³, R⁴ and R⁵ areindependently selected from the group consisting of C₁₋₆ alkyl groups,C₄₋₁₀ cycloalkyl groups, C₆₋₁₀ aryl groups, X is selected from the groupconsisting of linear, branched-chain or cyclic C₁₋₆ alkyl groups, C₆₋₁₀aryl groups, mono- or polyunsaturated linear, branched-chain or cyclicC₂₋₆ alkenyl groups, a trialkylsilyl (—SiR³R⁴R⁵), arylsulfonyl(R¹²—SO₂R³) group, and R¹ and R² are C₆₋₁₀ aryl groups or C₁₋₆ alkyl andcycloalkyl groups.

In particular, R³, R⁴ and R⁵ may be independently selected from thegroup consisting of methyl, ethyl, butyl, cyclohexyl, phenyl, andcombinations thereof, or R³, R⁴ and R⁵ may be the same and be selectedfrom the group consisting of methyl, ethyl, butyl, cyclohexyl, phenyl,and combinations thereof, especially cyclohexyl and phenyl.

In the metal complexes, X may be selected from the group consisting ofmethyl, ethyl, cyclohexyl, phenyl, p-tolyl, trimethylsilyl,p-tolylsulfonyl, or combinations thereof.

Also, R¹ and R² may be independently selected from the group consistingof phenyl, cyclohexyl, methyl, tert-butyl, and combinations thereof.

Advantageous ligands may be, in particular, ligands of the aboveformulas (I) or (II) with the substituents according to the followingTable 1:

No. R1, R2 On X 1 tert-butyl PPh3 phenyl 2 phenyl PPh3 phenyl 3 methylPPh3 phenyl 4 cyclohexyl PPh3 phenyl 5 tert-butyl PCy3 phenyl 6 phenylPCy3 phenyl 7 methyl PCy3 phenyl 8 cyclohexyl PCy3 phenyl 9 tert-butylPPh3 methyl 10 phenyl PPh3 methyl 11 methyl PPh3 methyl 12 cyclohexylPPh3 methyl 13 tert-butyl PCy3 methyl 14 phenyl PCy3 methyl 15 methylPCy3 methyl 16 cyclohexyl PCy3 methyl 17 tert-butyl PPh3 trimethylsilyl18 phenyl PPh3 trlmethylsilyl 19 methyl PPh3 trimethylsilyl 20cyclohexyl PPh3 trimethylsilyl 21 tert-butyl PCy3 trimethylsilyl 22phenyl PCy3 trimethylsilyl 23 methyl PCy3 trimethylsilyl 24 cyclohexylPCy3 trimethylsilyl 25 tert-butyl PPh3 tolylsulfonyl SO2Tol 26 phenylPPh3 tolylsulfonyl SO2Tol 27 methyl PPh3 tolylsulfonyl SO2Tol 28cyclohexyl PPh3 tolylsulfonyl SO2Tol 29 tert-butyl PCy3 tolylsulfonylSO2Tol 30 phenyl PCy3 tolylsulfonyl SO2Tol 31 methyl PCy3 tolylsulfonylsd2Tol 32 cyclohexyl PCy3 tolylsulfonyl SO2Tol

wherein PPh3 represents triphenylphosphine, and PCy3 representstricyclohexyl-phosphine.

The metal complexes may be, in particular, precious metal or transitionmetal complexes or precious metal or transition metal compounds. Inparticular, metals of group 10 or 11 of the Periodic Table of Elementsmay be employed.

In one embodiment, the metals platinum, palladium and nickel, preferablypalladium, may be used.

In another embodiment, the metals copper, silver and gold, preferablygold, may be used.

The metal complexes may also have further ligands, such as neutralelectron donor ligands, for example, dibenzylideneacetone (DBA), carbonmonoxide CO, NHC ligands, phosphines, such as triphenylphosphine ortricyclohexylphosphine, and amines, such as triethylamine ortributylamine. Also, charged ligands, such as halogens, especiallychloride, bromide and iodide, or the pseudohalides mesylate, triflate,acetate, may be present. Substituted or unsubstituted aryl and allylligands may also be present, as can mono- or diolefins, which may belinear or cyclic, such as cyclooctadiene.

Thus, advantageously, the metal complexes may additionally include, inparticular, ligands selected from the group consisting ofdibenzylideneacetone (DBA), carbon monoxide CO, triphenylphosphine,tricyclohexylphosphine, triethylamine, tributylamine, pyridyl, chloride,bromide, iodide, mesylate, triflate, acetate, allyl, phenyl, p-tolyl,o-tolyl, mesityl, cyclooctadiene, and combinations thereof.

In particular, metal complexes from the following Tables B to G may beemployed.

Table B

Table B shows platinum complexes with at least one of the 32 phosphaneligands set forth in Table A, and one or more of the ligands selectedfrom the group consisting of dibenzylideneacetone (DBA), carbon monoxideCO, triphenyl-phosphine, tricyclohexylphosphine, triethylamine,tributylamine, pyridyl, chloride, bromide, iodide, mesylate, triflate,acetate, allyl, phenyl, p-tolyl, o-tolyl, mesityl, cyclooctadiene, andcombinations thereof.

Table C

Table C shows palladium complexes with at least one of the 32 phosphaneligands set forth in Table A, and one or more of the ligands selectedfrom the group consisting of dibenzylideneacetone (DBA), carbon monoxideCO, triphenyl-phosphine, tricyclohexylphosphine, triethylamine,tributylamine, pyridyl, chloride, bromide, iodide, mesylate, triflate,acetate, allyl, phenyl, p-tolyl, o-tolyl, mesityl, cyclooctadiene, andcombinations thereof.

Table D

Table D shows nickel complexes with at least one of the 32 phosphaneligands set forth in Table A, and one or more of the ligands selectedfrom the group consisting of dibenzylideneacetone (DBA), carbon monoxideCO, triphenylphosphine, tricyclohexylphosphine, triethylamine,tributylamine, pyridyl, chloride, bromide, iodide, mesylate, triflate,acetate, allyl, phenyl, p-tolyl, o-tolyl, mesityl, cyclooctadiene, andcombinations thereof.

Table E

Table E shows copper complexes with at least one of the 32 phosphaneligands set forth in Table A, and one or more of the ligands selectedfrom the group consisting of dibenzylideneacetone (DBA), carbon monoxideCO, triphenylphosphine, tricyclohexylphosphine, triethylamine,tributylamine, pyridyl, chloride, bromide, iodide, mesylate, triflate,acetate, allyl, phenyl, p-tolyl, o-tolyl, mesityl, cyclooctadiene, andcombinations thereof.

Table F

Table F shows silver complexes with at least one of the 32 phosphaneligands set forth in Table A, and one or more of the ligands selectedfrom the group consisting of dibenzylideneacetone (DBA), carbon monoxideCO, triphenylphosphine, tricyclohexylphosphine, triethylamine,tributylamine, pyridyl, chloride, bromide, iodide, mesylate, triflate,acetate, allyl, phenyl, p-tolyl, o-tolyl, mesityl, cyclooctadiene, andcombinations thereof.

Table G

Table G shows gold complexes with at least one of the 32 phosphaneligands set forth in Table A, and one or more of the ligands selectedfrom the group consisting of dibenzylideneacetone (DBA), carbon monoxideCO, triphenylphosphine, tricyclohexylphosphine, triethylamine,tributylamine, pyridyl, chloride, bromide, iodide, mesylate, triflate,acetate, allyl, phenyl, p-tolyl, o-tolyl, mesityl, cyclooctadiene, andcombinations thereof.

The metal complexes can be obtained in a per se known manner, such as byreacting metal salts or metal complexes, which advantageously alreadybear desirable further ligands (such as nickel tetracarbonyl, (THT)AuCl(THT=tetra-hydrothiophene), allylpalladium(II) chloride dimer, palladiumacetate, palladium chloride, or tris(dibenzylideneacetone)dipalladium(0)x dibenzylideneacetone), with one or more phosphane ligands, optionallyin a suitable solvent.

The metal complexes described above may be employed in homogeneouscatalysis, especially in coupling reactions, wherein said couplingreaction may be selected from the group consisting of

(i) catalytic hydrofunctionalization reactions of alkynes and alkenes;

(ii) catalytic hydroamination reactions of alkynes and alkenes;

(iii) catalytic O—H addition reactions to alkynes and alkenes;

(iv) catalytic coupling reactions;

(v) catalytic Suzuki coupling reactions, especially for the preparationof biaryls;

(vi) catalytic cross-coupling reactions, especially C—N and C—O couplingreactions; and/or

(vii) catalytic Heck coupling reactions, especially for the preparationof arylated olefins, and Sonogashira coupling reactions, especially forthe preparation of arylated and alkenylated alkynes.

In addition, the metal complexes may be palladium allyl complexes havingthe structure (V) or palladium aryl complexes having the structure (VI):

wherein X is an anion,

Y, R¹, R² may be defined as in the preceding items,

R³³, R³⁴ and R³⁵ may be independently selected from H, alkyl, aryl andheteroaryl groups that may be unsubstituted or substituted withfunctional groups; or at least two of R³³, R³⁴ and R³⁵ form acarbocyclic ring with 5 to 14 carbon atoms,

Ar represents a substituted or unsubstituted, especially a substituted,aryl group.

Thus, R³³, R³⁴ and R³⁵ may be independently selected from linear,branched-chain or cyclic C₁₋₁₀ alkyl groups, preferably from C₁₋₆ alkylgroups or C₄₋₁₀-cycloalkyl groups, the aryl groups are selected fromC₆₋₁₄ aryl groups, preferably from C₆₋₁₀ aryl groups, the alkenyl groupsare selected from mono- or polyunsaturated linear, branched-chain orcyclic C₂₋₁₀ alkenyl groups, preferably from C₂₋₆ alkenyl groups, andthe heteroaryl groups are selected from C₆₋₁₄ heteroaryl groups,preferably from C₆₋₁₀ heteroaryl groups having 1 to 5 heteroatomsselected from N, O and S, wherein all of the groups mentioned above maybe substituted with functional groups; and/or

at least two of R³³, R³⁴ and R³⁵ form a carbocyclic ring that is a C₄₋₁₀cycloalkyl group, or a C₆₋₁₄ aryl group, which may be substituted withone or more functional groups; and

Ar are selected from C₆₋₁₄ aryl groups, preferably C₆₋₁₀ aryl groups,and the heteroaryl groups are selected from C₆₋₁₄ heteroaryl groups,preferably from C₆₋₁₀ heteroaryl groups having 1 to 5 heteroatomsselected from N, O and S, wherein all of the groups mentioned above maybe substituted with functional groups; and

the functional groups are selected from alkyl (—R¹¹), especially C₁₋₆alkyl groups, C₆₋₁₀ aryl (—R¹²), halogen (-Hal), hydroxy (—OH), cyano(—CN), alkoxy (—OR³), amino (—NR¹² ₂, —NHR¹¹, —NH₂), mercapto (—SH,—SR¹¹), wherein R¹¹, independently of further R¹¹ residues, is selectedfrom C₁₋₆ alkyl residues.

In particular, X may be selected from the group of halogen, tosylate,nosylate and mesylate, especially X may be selected from the group offluorine, chlorine, bromine, iodine, tosylate, nosylate and mesylate,and/or aryl may be selected from phenyl, m-tolyl, p-tolyl, o-tolyl,mesityl, 1,3-diisopropylphenyl.

Palladium complexes containing at least one of the phosphane ligandsdescribed above, especially the palladium allyl complexes and palladiumaryl complexes may be employed in homogeneous catalysis, especially incoupling reactions, wherein said coupling reaction may be selected fromthe group consisting of

(i) catalytic hydrofunctionalization reactions of alkynes and alkenes;

(ii) catalytic hydroamination reactions of alkynes and alkenes;

(iii) catalytic O—H addition reactions to alkynes and alkenes;

(iv) catalytic coupling reactions;

(v) catalytic Suzuki coupling reactions, especially for the preparationof biaryls;

(vi) catalytic cross-coupling reactions, especially C—N and C—O couplingreactions; and/or

(vii) catalytic Heck coupling reactions, especially for the preparationof arylated olefins, and Sonogashira coupling reactions, especially forthe preparation of arylated and alkenylated alkynes.

In addition, the patent application relates to a process for performinga coupling reaction containing the steps of

-   -   providing a reaction mixture containing at least a substrate,        coupling partner, and at least one of the above metal complexes,        or a metal complex containing one of the above described        ligands; and    -   reacting said substrate with said coupling partner in the        presence of the metal complex or its derivative to form a        coupling product.

Here too, the metal of the metal complex as described above may be aprecious metal and/or a transition metal, especially a metal of group 10or 11 of the Periodic Table of the elements, where it has proven usefulif the metal of the metal complex is selected from the group consistingof copper, silver, gold, platinum, palladium, nickel, and combinationsthereof.

The substrate may be a substituted aromatic compound, and in particular,the substituted aromatic compound may be an aromatic or heteroaromaticcompound.

It may be substituted, inter alia, with a leaving group, or anunsaturated aliphatic group, or a leaving group, where it has provenuseful if said leaving group is selected from the group consisting ofhalogen, tosylate, nosylate and mesylate, and/or said unsaturatedaliphatic group is selected from the group consisting of alkene oralkyne, especially with 2 to 12, especially with 2 to 8, carbon atoms.

The coupling partner may comprise an organometallic compound, especiallywhich may be selected from the group consisting of organic boroncompounds, organolithium compounds, organozinc compounds, organolithiumcompounds, and Grignard compounds, wherein advantageously saidorganometallic compound includes at least one aromatic residue, orwherein said organometallic compound includes at least one unsaturatedaliphatic residue, or wherein said organometallic compound includes atleast one saturated aliphatic residue.

Also, the patent application relates to such a process wherein thecoupling reaction is selected from the group consisting of

(i) catalytic hydrofunctionalization reactions of alkynes and alkenes;

(ii) catalytic hydroamination reactions of alkynes and alkenes;

(iii) catalytic O—H addition reactions to alkynes and alkenes;

(iv) catalytic coupling reactions;

(v) catalytic Suzuki coupling reactions, especially for the preparationof biarls;

(vi) catalytic cross-coupling reactions, especially C—N and C—O couplingreactions; and/or

(vii) catalytic Heck coupling reactions, especially for the preparationof arylated olefins, and Sonogashira coupling reactions, especially forthe preparation of arylated and alkenylated alkynes.

The invention is further explained by means of the following Examples.They are exemplary for the preparation of the ylide-functionalizedphosphanes, their transition metal complexes, and the use thereof incatalysis, and they are by no means to be understood as limiting thescope of protection of the invention.

EXAMPLES Example 1: Preparation of Ylide-Functionalized Phosphanes A)Preparation Through Metallated Ylides with Monochlorophosphanes (RouteA)

Preparation of the ylide-functionalized bis(cyclohexyl)phosphane withOn=PPh₃, R=R′=Cy, X=SO₂Tol from the metallated ylide [Ph₃PCSO₂Tol]Na

2.05 g (4.5 mmol) of the metallated ylide [Ph₃PCSO₂Tol]Na was dissolvedin 40 ml of THF and cooled down to −50° C. At this temperature, 1.13 ml(5.4 mmol) of dicyclohexylchlorophosphanes was slowly added to theyellow reaction solution, which finally bleached when warmed up to roomtemperature. After the solvent has been removed under vacuum, thecolorless solid formed was taken up in 30 ml of toluene, and thesuspension was filtered. Renewed reduction of the solvent resulted inthe formation of a solid. The latter was filtered off, whereby theproduct could be obtained as a colorless solid (yield: 1.97 g, 3.2 mmol,71%).

¹H-NMR (250 MHz, THF-d⁸): δ=0.78-1.29 (m, 10H, CH_(Cy)), 1.47-1.79 (m,10H, CH_(Cy)), 2.13-2.23 (m, 2H, CH_(Cy)), 2.31 (s, 3H, CH_(STol)),6.90-7.10 (m, 4H, CH_(STol), meta/ortho), 7.35-7.61 (m, 9H, CH_(PPh),meta/para), 7.65-7.78 (m, 6H, CH_(PPh), ortho). ³¹P{¹H}-NMR (250 MHz,THF-d⁸): δ=−5.79 (d, ²J_(PP)=164.3 Hz: PCy), 25.58 (d, ²J_(PP)=164.4 Hz;PPh₃). TEP=2055.1 cm⁻¹.

The preparation of the simple ylide-functionalized phosphanes was alsoeffected according to this protocol, with:

On=PPh₃, X=SO₂Tol, R=R′=Ph (T. Scherpf et al., Angew. Chem. Int. Ed.,54, 8542 (2015)), iPr, adamantyl or cyclohexyl

On=PPh₃, X=CN, R=R′=Ph, or Cy.

In addition, the bis(ylide)-functionalized phosphane Y₂PPh with On=PPh₃and X=CN was prepared according to this protocol.

B) Preparation Through the Dichlorophosphane Intermediate (Route A)

Preparation of the ylide-functionalized dimethylphosphane with On=PPh₃,R=R′=Me, X=SO₂Tol from the metallated ylide [Ph₃PCS₂Tol]Na

In a 50 ml Schlenk tube, 3.01 g (6.66 mmol) of the metallated ylide wasdissolved in 35 ml of THF. Thereafter, 0.70 ml (1.10 g, 7.99 mmol) ofphosphorus trichloride was quickly added dropwise and heated to boil for5 min. After the reaction solution had been stirred over night, thesolvent was removed under vacuum, and the solid was dissolved indichloromethane. Subsequently, the suspension was filtered through afilter cannula, and the solvent was again removed under vacuum. Thesolid that had precipitated was washed with benzene, filtered offthrough a Schlenk frit, and dried under vacuum. The ylide-functionalizeddichlorophosphane can thus be obtained as a colorless solid (yield: 2.88g, 5.44 mmol, 82%).

¹H-NMR (500.1 MHz, CD₂Cl₂): δ [ppm]=2.37 (s, 3H; CH₃), 7.04-7.07 (m, 2H;CH_(Tol,meta)), 7.22-7.25 (m, 2H; CH_(Tol,ortho)), 7.49-7.55 (m, 6H;CH_(PPh,meta)), 7.64-7.69 (m, 3H; CH_(PPh,para)), 7.71-7.77 (m, 6H;CH_(PPh,ortho)). ¹³C{¹H}-NMR (125.8 MHz, CD₂Cl₂): δ [ppm]=21.5 (s, CH₃),62.9 (dd, ¹J_(CP)=111.8 Hz, ¹J_(CP)=91.8 Hz; C_(PCS)), 124.1 (dd,¹J_(CP)=92.8 Hz, ³J_(CP)=3.6 Hz; C_(PPh,ipso)), 129.1 (s,CH_(Tol,meta)), 129.2 (d, ³J_(CP)=12.8 Hz; CH_(PPh,meta)), 129.7 (d,⁴J_(CP)=1.9 Hz; CH_(Tol,ortho)), 133.5 (d, ⁴J_(CP)=2.9 Hz;CH_(PPh,para)), 135.2 (dd, ²J_(CP)=10.2 Hz, ⁴J_(CP)=1.9 Hz;CH_(PPh,ortho)), 142.4 (s, C_(Tol,para)), 143.9 (s, C_(Tol,ipso)).³¹P{¹H}-NMR (162.0 MHz, CD₂Cl₂): δ [ppm]=19.7 (d, ²J_(PP)=110.1 Hz),159.2 (br).

In a 50 ml Schlenk tube, 299 mg (0.56 mmol) of the ylide-functionalizeddichlorophosphane was dissolved in 10 ml of THF, and 2.35 ml (1.13 mmol,0.48 M) of methyllithium in THF was slowly added. After stirring thesolution over night, the solvent was removed under vacuum, and theresidue was dissolved in 15 ml of benzene. Thereafter, the suspensionwas filtered through a filter cannula, and the solvent was again removedunder vacuum. After vacuum drying, the dimethylphosphane can be isolatedas a colorless solid (0.38 g, 0.78 mmol; 82%).

¹H-NMR (500.1 MHz, C₆D₆): δ [ppm]=1.70 (s, 6H; CH_(3,PMe)), 1.96 (s, 3H;CH_(3,Tol)), 6.74-6.75 (m, 2H; CH_(Tol,meta)), 6.96-6.99 (m, 6H;CH_(PPh,meta)), 7.03-7.05 (m, 3H; CH_(PPh,para)), 7.59-7.60 (m, 2H;CH_(Tol,ortho)), 7.75-7.77 (m, 6H; CH_(PPh,ortho)). ¹³C{¹H}-NMR (125.8MHz, C₆D₆): δ [ppm]=16.0 (dd, ¹J_(CP)=13.9 Hz, ³J_(CP)=6.5 Hz;CH_(3,PMe)), 21.1 (s, CH_(3,Tol)), 42.2 (dd, ¹J_(CP)=107.8 Hz,¹J_(CP)=53.7 Hz; C_(PCS)), 126.9 (s, CH_(Tol,ortho)), 128.3 (d,³J_(CP)=12.0 Hz; CH_(PPh,meta)), 128.6 (s, CH_(Tol,meta)), 131.7 (d,⁴J_(CP)=2.8 Hz; CH_(PPh,para)), 135.0 (dd, ²J_(CP)=9.5 Hz, ⁴J_(CP)=2.5Hz; CH_(PPh,ortho)), 139.8 (s, C_(Tol,para)), 148.5 (S, C_(Tol,ipso)).³¹P{¹H}-NMR (162.0 MHz, C₆D₆): δ [ppm]=−46.4 (d, ²J_(PP)=146.5 Hz), 23.6(d, ²J_(PP)=146.5 Hz). TEP=2059.7 cm⁻¹.

The preparation of the simple ylide-functionalized phosphanes withOn=PPh₃, X=SO₂Tol or CN, R=R′=Ph, Me, iPr or Cy was effected accordingto this protocol.

In addition, the ylide-functionalized phosphane Y₂PCy with On=PPh₃ andX=CN was prepared according to this protocol.

C) Preparation by Phosphorylation and Deprotonation of Onium Salts(Route B)

The corresponding onium salts are either commercially available, or canbe prepared by standard synthesis methods, such as the quaternization ofcorresponding phosphane, sulfide or amine precursors with alkyl halidesand tosylates. The salts (such as A in the following Scheme) can bedeprotonated with metal bases, such as potassium tert-butanolate, metalhydrides or lithium/sodium/potassium bis(trimethylsilyl)amide, anddirectly react with the halophosphane to form the phosphanyl-substitutedonium salt (e.g., B). The latter can be converted to the desiredylide-functionalized phosphane with another equivalent of base withoutprior processing. Simple representatives can be obtained from thecommercially available bis(diphenylphosphino)methane andbis(dicyclohexylphosphino)methane by quaternization with alkyl halidesfollowed by deprotonation (J. Langer et al., ARKIVOC, 3, 210 (2012)).Other functionalizations can be realized according to the followingScheme. In particular, phosphanes, sulfides, amines, imines,N-heterocycles and sulfoxides have proven useful as the On moiety.

D) Examples: Synthesis of a methyl-(Z=Me) and silyl-functionalized(Z=SiMe₃) ylide phosphane

The onium salt A (here: ethyltriphenylphosphonium iodide) with X=Me andHal=I can be prepared according to known literature protocols (M. N.Alberti et al., Org. Lett., 10, 2465 (2008)), or can be purchased (CAS:4736-60-1). The formation of the ylide-functionalized phosphaneY_(Me)PCy₂ with R=Cy is effected in accordance with:

190 g (4.50 mmol) of ethyltriphenylphosphonium iodide and 500 mg (12.5mmol) of potassium hydride were added to 20 ml of THF. The suspensionwas heated at 60° C. for 4 hours, whereupon formation of hydrogen couldnot be observed any more. Subsequently, 1.60 g (5.0 mmol) ofdicyclohexyliodophosphane was added dropwise, and the mixture was againheated at 60° C. for 16 hours. After the solvent had been removed undervacuum, 20 ml of hexane was added. The mixture was heated to the boilingpoint and filtered while still hot. The solvent was again removed undervacuum, and the residual solid was dissolved in as low as possible anamount of a 1:1 mixture of hexane and toluene. By storing the solutionat −75° C. for three days, the desired phosphane could be isolated as anorange crystalline solid (1.63 g, 3.35 mmol, 74%).

¹H NMR: (400.1 MHz, CD₂Cl₂): δ=1.20-1.59 (m, 10H, Cy), 1.70-1.89 (m, 6H,Cy), 1.89-2.07 (m, 4H, Cy), 2.11 (dd, 3H, ³J_(HP)=16.3 Hz, ³J_(HP)=2.4Hz, CH₃), 2.21-2.30 (m, 2H, Cy), 7.05-7.10 (m, 9H, CH_(PPh, ortho) andCH_(PPh, para)), 7.69-7.79 (m, 6H, CH_(PPh, meta)), ³¹P{¹H}-NMR: (162.1MHz, CD₂Cl₂): δ=−2.44 (d, ²J_(PP)=176.8 Hz, PCy₂), 25.4 (d,²J_(PP)=176.8 Hz, PPh₃). TEP: 2050.1 cm⁻¹.

The preparation of the ylide-functionalized phosphanes with On=PPh₃,X=Et, CH₂Ph, Cy, SiMe₃, R=R′=Ph, Me or Cy was also effected according tothis protocol.

2.00 g (4.20 mmol) of trimethylsilylmethylenephenylphosphonium iodideand 250 mg (6.23 mmol) of potassium hydride were added to 20 ml of THF.The suspension was stirred at room temperature for 16 hours, whereuponformation of hydrogen could not be observed any more. The yellowsuspension was filtered, washed with 5 ml of THF, and transferred into adropping funnel, and slowly added to a solution ofdicyclohexyliodophosphane (1.5 g, 4.63 mmol) in 20 ml of toluene at −78°C. The solution was slowly heated to room temperature and then stirredfor 24 h. The solid that had precipitated was filtered off and washedtwice with 5 ml of toluene, and dried under vacuum. The solid and 670 mgof KHMDS (3.36 mmol) were dissolved in 20 ml of THF and stirred for 1hour. The solid that had precipitated was removed by filtration, thesolvent was removed under vacuum, and the residual solid was dissolvedin 50 ml boiling hexane and filtered while still hot. The solution wasslowly cooled down to RT and allowed to stand for 16 hours. The solutionabove the yellow crystals that had formed was removed, and the crystalswere washed three times with 5 ml of cold hexane, followed by dryingunder vacuum (1.07 g, 1.98 mmol, 47%).

¹H NMR: (400.1 MHz, C₆D₆): δ=0.28 (s, 6.3H, SiMe₃, trans), 0.40 (s,2.7H, SiMe₃, cis), 0.89-2.25 (m, 20H, Cy), 2.34-2.60 (m, 2H, Cy),7.02-7.11 (m, 9H, CH_(PPh, ortho) and CH_(PPh, para)), 7.73-7.82 (m, 6H,CH_(PPh, meta)), ³¹P{¹H}-NMR: (162.1 MHz, C₆D₆): δ=8.3 (d, ²J_(PP)=37.2Hz, PCy₂, cis), 12.8 (d, ²J_(PP)=172.2 Hz, PCy₂, trans), 19.7 (d,²J_(PP)=37.2 Hz, PPh₃, cis), 29.1 (d, ²J_(PP)=172.2 Hz, PPh₃, trans),TEP: 2048.9 cm⁻¹.

4.00 g (10 mmol) of ethyltriphenylphosphonium iodide and 600 mg (15mmol) of potassium hydride were added to 20 ml of THF. The suspensionwas stirred at room temperature for 16 hours, whereupon formation ofhydrogen could not be observed any more. The red suspension wasfiltered, washed with 5 ml of THF, and transferred into a droppingfunnel, and slowly added dropwise to a solution ofcyclohexyldichlorophosphane (460 mg, 2.5 mmol) in 20 ml of THF withvigorous stirring. The solution was stirred at RT for 16 hours. Thesolid that had precipitated was filtered off and washed twice with 10 mlof THF. The solvent of the red solution obtained was removed undervacuum, and the solid obtained was dried under vacuum. 20 ml ofcyclohexane was added, the mixture was heated to boil, filtered whilestill hot, and then slowly cooled down to RT, wherein a red solidprecipitated. The supernatant solution was removed, and the solid waswashed twice with 2 ml of pentane and dried under vacuum (0.68 g, 0.98mmol, 39%).

¹H NMR: (400.1 MHz, C₆D₆): δ=1.17-1.36 (m, 3H, Cy,), 1.47-1.60 (m, 2H,Cy,), 1.70-1.80 (m, 1H, Cy,), 1.84-1.94 (m, 2H, Cy,), 2.22-2.32 (m, 2H,Cy), 2.52 (dd, ³J_(HP)=17.4 Hz, ³J_(HP)=2.0 Hz 6H, Me), 2.75-2.86 (m,1H, Cy), 7.98-7.04 (m, 12H, CH_(PPh, ortho)), 7.04-7.11 (m, 6H,CH_(PPh, para)), 7.62-7.70 (m, 12H, CH_(PPh, meta)), ³¹P{¹H}-NMR: (162.1MHz, C₆D₆): δ=−20.3 (t, ²J_(PP)=175.1 Hz, PCy), 19.5 (d, ²J_(PP)=175.1Hz, PPh₃)

In a Schlenk flask, 10.0 g (22.9 mmol) of ethyltricyclohexylphosphoniumiodide was suspended in 75 ml of THF. The Suspension was cooled in anice bath to 0° C., 14.5 ml (22.9 mmol) of a 1.58 M solution of n-BuLi inhexanes was slowly added dropwise. The solution, which was clear now,was warmed up to room temperature, and 2.45 ml (2.67 g, 11.5 mmol) ofdicyclohexylphosphane chloride was added. A colorless solid precipitatedimmediately, and the suspension was heated at 60° C. for 16 hours. Thecolorless solid was filtered off and washed twice with 20 ml each ofTHF, and stored under argon. The filtrate was dried under vacuum, andthe resulting solid was dissolved in 100 ml of cyclohexane, filtered,and the cyclohexane was again removed under vacuum. After drying undervacuum, the product could be isolated as a colorless solid (4.93 g, 9.77mmol, 85%).

Numbering Scheme

¹H NMR (400 MHz, C₆D₆) 6=1.08-1.23 (m, 9H, CH_(2, PCy3, H3+H4)),1.32-1.43 (i, 2H, CH_(2, PCy2, H4)), 1.43-1.58 (m, 12H,CH_(2, PCy3, H2+PCy2, H2+H3)), 1.58-1.66 (m, 5H,CH_(2, PCy3, H4+PCy2, H2)), 1.67-1.79 (m, 6H, CH_(2, PCy3, H3)),1.76-1.83 (m, 2H, CH_(2, PCy2, H4)), 1.82-1.96 (m, 11H,CH_(2, PCy3, H2+PCy2, H2)+CH₃), 1.95-2.09 (m, 4H, CH_(2, PCy3, H3)+CH,_(PCy2, H1)), 2.11-2.23 (m, 2H, CH_(2, PCy2, H2)), 2.23-2.34 (m, 2H,CH_(2, PCy2, H3)), 2.34-2.52 (m, 3H, CH, _(PCy3, H1)) ppm. ¹³C {¹H} NMR(101 MHz, C₆D₆) δ=−1.7 (dd, ¹J_(CP)=108.8 Hz, ¹J_(CP)=21.1 Hz, P—C⁻—P),14.8 (dd, ²J_(CP)=8.4 Hz, ²J_(CP)=0.7 Hz, CH₃), 26.6-27.0 (m,CH_(2, PCy3, C4)), 27.7-27.8 (m, CH_(2, PCy2, C4)), 27.8 (d,³J_(CP)=11.0 Hz, CH_(2, PCy3, C3)), 28.0-28.4 (m, CH_(2, PCy3, C2)),28.5 (d, ³J_(CP)=11.8 Hz, CH_(2, PCy2, C3)), 29.0 (d, ³J_(CP)=8.1 Hz,CH_(2, PCy2, C3)), 32.9 (d, ²J_(CP)=9.9 Hz, CH_(2, PCy2, C2)), 33.67(dd, ¹J_(CP)=49.5 Hz, ³J_(CP)=8.9 Hz, CH, _(PCy3, C1)) 33.69 (d,²J_(CP)=19.8 Hz, CH_(2, PCy2, C2)), 38.4 (dd, ¹J_(CP)=13.8 Hz,³J_(CP)=5.3 Hz, CH, _(PCy2, C1)) ppm. ³¹P {¹H} NMR (162 MHz, C₆D₆) δ=1.0(d, ²J_(PP)=128.9 Hz, PCy₂), 30.6 (d, ²J_(PP)=128.9 Hz, PCy₃) ppm. CHNS:calculated: C: 76.14, H: 11.58. measured: C: 75.62, H: 11.32.

Recovery of Ethyltricyclohexylphosphonium Iodide

The colorless solid remaining after the washing with THE was dried undervacuum and dissolved in 15 ml of DCM. The solution was filtered, and thesolvent was removed under vacuum, and dried.Ethyltricyclohexylphosphonium iodide was obtained as a colorless solid(4.27 g, 9.8 mmol, 85%).

In a Schlenk flask, 2.55 g (5.84 mmol) of ethyltricyclohexylphosphoniumiodide was suspended in 25 ml of THF. The suspension was cooled in anice bath to 0° C., and 2.78 ml (5.84 mmol) of a 2.1 M solution of n-BuLiin hexanes was slowly added dropwise. The solution, which was clear now,was warmed up to room temperature. 0.55 ml (0.53 g, 2.92 mmol) ofdi-tert-butylchlorophosphane was added, and the mixture was heated at60° C. for 16 hours. The colorless solid was filtered off and washedtwice with 5 ml each of THE. The filtrate was dried under vacuum, andthe resulting solid was dissolved in 50 ml of cyclohexane. After renewedfiltration, the solvent was removed under vacuum, and the product wasisolated as a colorless solid (1.32 g, 1.51 mmol, 52%; non-optimizedyield).

¹H NMR (400 MHz, C₆D₆) δ=1.08-1.24 (m, 9H, CH_(2, Cy, H3+H4)), 1.54 (d,³JHP=10.7 Hz, 18H, CH3, tBu), 1.44-1.67 (m, 9H, CH_(2, Cy, H2+H4)),1.63-1.76 (m, 6H, CH_(2, Cy, H3)), 2.04 (d, ³J_(PH)=13.0 Hz, 6H,CH_(2, Cy, H2)), 2.11 (dd, ³J_(HP)=13.8 Hz, ³J_(HP)=3.1 Hz, 3H, CH₃),2.16-2.32 (m, 3H, CH, _(Cy, H1)) ppm. 13C {¹H} NMR (101 MHz, C₆D₆) δ=4.5(dd, ¹J_(CP)=102.9 Hz, ¹J_(CP)=27.3 Hz, P—C⁻—P), 18.2 (dd, ²J_(CP)=8.6Hz, ²J_(CP)=0.6 Hz, CH3), 27.0 (CH_(2, Cy, C4)), 28.2 (d, ³J_(CP)=10.6Hz, CH_(2, Cy, C3)), 29.6-29.8 (m, CH_(2, Cy, C2)), 33.3 (d,²J_(CP)=14.4 Hz, CH3, tBu), 36.5 (dd, ¹J_(CP)=23.4 Hz, ¹J_(CP)=6.6 Hz,C,_(tBu)) 37.0 (dd, ¹J_(CP)=47.9 Hz, ³J_(CP)=9.0 Hz, CH, _(Cy, C1)) ppm.³¹P {¹H} NMR (162 MHz, C₆D₆) δ=26.4 (d, ²J_(PP)=146.9 Hz, PtBu₂), 30.4(d, ²J_(PP)=146.9 Hz, PCy₃) ppm.

In a Schlenk tube, 500 mg (1.11 mmol) of benzyltricyclohexylphosphoniumiodide was weighed and suspended in 10 mL of THF. To the suspension,0.51 ml (1.11 mmol; 1 eq.) of an n-BuLi solution (2.18 M in hexane) wasslowly added dropwise until a clear solution had formed. The solutionwas stirred for 45 min, and subsequently 0.32 ml (335 mg; 1.44 mmol; 1.3eq.) of Cy₂PCl was added. The suspension was stirred at room temperaturefor 16 hours. The solid was filtered off and washed twice with 10 mleach of THF, und dried under high vacuum for 1.5 hours (558 mg). Thesolid obtained as well as 133 mg (1.19 mmol) of potassiumtert-butanolate were weighed in a Schlenk tube and suspended in 20 ml ofdry toluene. The suspension was stirred for 16 hours and then filteredoff. The solid was washed twice with 10 ml of toluene. The solvent ofthe filtrate was removed under vacuum, and the product was obtained as acolorless solid (0.35 g, 0.62 mmol, 56%; non-optimized yield).

Numbering Scheme

¹H NMR (400 MHz, Tol-d₈) δ=1.00-1.22 (m, 9H, CH_(2, PCy3, H3+H4)),1.22-1.64 (m, 19H, CH_(2, PCy2, H2+H3+H4 PCy3, H2, H3)), 1.64-1.83 (m,12H, CH_(2, PCy2, H3+H4 PCy3, H3)), 1.83-2.01 (m, 10H,CH_(2, PCy2, H2 PCy3, H2)), 2.33-2.46 (m, 5H, CH,_(PCy2, H1, PCy3, H1)), 6.97-7.00 (m, 1H, CH, _(Ph, para)), 7.18-7.25(m, 2H, CH, _(Ph, meta)), 7.34 7.40 (m, 2H, CH, _(Ph, ortho)) ppm.³¹P{¹H}-NMR (162.1 MHz, Tol-d₈): δ [ppm]=−5.4 (d, ²J_(PP)=132.0 Hz,PtBu₂), 21.5 (d, ²J_(PP)=132.0 Hz,) ppm.

Example 2: Preparation of Transition Metal Complexes of theYlide-Functionalized Phosphanes

A) Nickel Carbonyl Complexes

By way of example, the synthesis of the complex with theylide-functionalized phosphane with On=PPh₃, R=R′=Me, X=SO₂Tol asprepared in Example 1.B) Ph₃P S Tol

In a 30 ml Schlenk tube, 0.10 g (0.20 mmol) of the phosphane wassuspended in 5 ml of pentane. Thereafter, 0.43 ml (0.31 mmol) of 0.7 Mnickel tetracarbonyl in benzene was quickly added dropwise, and thereaction mixture was stirred at room temperature for 2 hours.Subsequently, the solvent was removed by means of a cannula, and thesolid was washed twice with 5 ml each of pentane. After removing thesolvent and drying under vacuum, the complex was obtained as a grayishsolid (79.1 mg, 0.13 mmol, 61%).

¹H-NMR (500.1 MHz, CD₂Cl₂): δ [ppm]=1.97 (d, ²J_(PH)=4.70 Hz, 6H;CH_(3,PMe)), 2.30 (s, 3H; CH_(3,Tol)), 6.93-6.95 (m, 2H; CH_(Tol,meta)),7.16-7.17 (m, 2H; CH_(Tol,ortho)), 7.38-7.42 (m, 6H; CH_(PPh,meta)),7.53-7.58 (m, 9H; CH_(PPh,ortho+para)). ¹³C{¹H}-NMR (125.8 MHz, CD₂Cl₂):δ [ppm]=21.4 (s, CH_(3,Tol)), 23.4 (dd, ¹J_(CP)=26.8 Hz, ³J_(CP)=3.5 Hz;CH_(3,PMe)), 39.1 (dd, ¹J_(CP)=105.6 Hz, ¹J_(CP)=3.2 Hz; C_(PCC)), 125.9(s, CH_(Tol,ortho)), 126.9 (dd, ¹J_(CP)=91.5 Hz, ³J_(CP)=1.9 Hz;C_(PPh,ipso)), 128.8 (d, ³J_(CP)=12.4 Hz; CH_(PPh,meta)), 129.0 (s,CH_(Tol,meta)), 132.8 (d, ⁴J_(CP)=3.0 Hz; C_(PPh,para)), 135.1 (d,²J_(CP)=9.8 Hz; CH_(PPh,ortho)), 140.7 (s, C_(Tol,para)), 146.7 (dd,³J_(CP)=1.21 Hz, ³J_(CP)=1.2 Hz; CH_(Tol,ipso)), 196.2 (s, C_(CO)).³¹P{¹H}-NMR (162.0 MHz, CD₂Cl₂): δ [ppm]=−11.8 (d, ²J_(PP)=75.6 Hz),20.3 (d, ²J_(PP)=75.6 Hz). Elemental analysis: measured: C, 58.41; H,4.51; S, 4.97. calculated: C, 58.80; H, 4.46; S, 5.06.

B) Gold Chloride Complexes

By way of example, the synthesis of the complex with theylide-functionalized diphenylphosphane with On=PPh₃, R=R′=Ph, X=SO₂Tolas prepared in Example 1.A) is described below.

In a 50 ml Schlenk tube, 0.20 g (3.26 mmol) of the phosphane and 0.11 g(3.26 mmol) of (THT)AuCl (THT=tetrahydrothiophene) were dissolved in 5ml of THF, and the reaction mixture was stirred at room temperature overnight to form a colorless precipitate. The solid was filtered offthrough a Schlenk frit and dried under vacuum to obtain the desired goldcomplex (0.32 g, 0.38 mmol, 77%).

¹H-NMR (500.1 MHz, CD₂Cl₂): δ [ppm]=2.27 (s, 3H; CH₃), 6.20-6.23 (m, 2H;CH_(Tol,ortho)), 6.70-6.72 (m, 2H; CH_(Tol,meta)), 7.41-7.51 (m, 12H;CH_(PPh,ortho+meta)), 7.61-7.62 (m, 2H; CH_(AuPPh,para)), 7.63-7.66 (m,7H; CH_(AuPPh,meta+PPh,para)), 7.86-7.90 (m, 4H; CH_(AuPPh,ortho)).¹³C{¹H}-NMR (125.8 MHz, CD₂Cl₂): δ [ppm]=21.3 (s, CH₃), 42.8 (dd,¹J_(CP)=101.4 Hz, ¹J_(CP)=57.6 Hz; C_(PCS)), 126.0 (dd, ¹J_(CP)=86.9 Hz,³J_(CP)=8.8 Hz; C_(PPh,ipso)), 126.0 (s, CH_(Tol,ortho)), 128.5 (dd,²J_(CP)=11.7 Hz, ⁴J_(CP)=0.8 Hz; CH_(PPh,ortho)), 128.9 (s,CH_(Tol,meta)), 129.1 (d, ³J_(CP)=12.5 Hz; C_(PPh,meta)), 131.1 (d,⁴J_(CP)=2.6 Hz; CH_(AuPPh,para)), 133.4 (d, ⁴J_(CP)=2.8 Hz;CH_(PPh,para)), 133.4 (dd, ¹J_(CP)=63.0 Hz, ³J_(CP)=8.2 Hz;C_(AuPPh,ipso)), 135.2 (d, ³J_(CP)=13.6 Hz; CH_(AuPPh,meta)), 135.4 (dd,²J_(CP)=9.2 Hz, ⁴J_(CP)=1.2 Hz; CH_(AuPPh,ortho)), 141.7 (s,C_(Tol,para)), 144.4 (s, CH_(Tol,ipso)). ³¹P{¹H}-NMR (162.0 MHz,CD₂Cl₂): δ [ppm]=21.4 (d, ²J_(PP)=68.3 Hz), 22.1 (d, ²J_(PP)=68.3 Hz).Elemental analysis: measured: C, 54.19; H, 3.90; S, 3.68. calculated: C,53.88; H, 3.81; S, 3.78.

All the gold-phosphane complexes used in the catalysis (see below) wereprepared according to this protocol.

C) Palladium Allyl Complexes

By way of example, the synthesis of three palladium allyl complexes ofthe ylide-substituted phosphanes is described here. Complexes with moreligands other than those stated here can be prepared according to thestated protocol.

Synthesis of the complex with the ylide-functionalized diphenylphosphanewith On=PPh₃, R=R′=Ph, X=SO₂Tol as prepared in Example 1.A):

In a 50 ml Schienk tube, 201 mg (0.325 mmol) of the phosphane and 59 mg(0.163 mmol) of the allylpalladium(II) chloride dimer were dissolved in10 ml of dichloromethane, and stirred at room temperature for 1 hour.The solvent was subsequently reduced to 1 ml under vacuum, and themixture was admixed with pentane until a solid precipitated. The latterwas filtered off through a Schlenk frit and subsequently dried undervacuum to obtain the palladium complex as a brownish solid (163 mg, 0.21mmol, 63%).

¹H-NMR (500.1 MHz, CD₂Cl₂): δ [ppm]=1.8-2.5 (br, 2H; CH_(2,allyl)), 2.22(s, 3H; CH₃), 2.76 (br, 1H; CH_(2,allyl)), 4.12 (m, 1H; CH_(2,allyl)),4.84 (br, 1H; CH_(allyl)), 6.71-6.73 (m, 2H; CH_(Tol,meta)), 6.76-6.78(m, 2H; CH_(Tol,ortho)), 7.16-7.18 (m, 4H; CH_(PdPPh,meta)), 7.22-7.25(m, 2H; CH_(PdPPh,para)), 7.41-7.45 (m, 6H; CH_(PPh,meta)), 7.53-7.57(m, 3H; CH_(PPh,para)), 7.84-7.88 (m, 4H; CH_(PdPPh,ortho)), 7.97-8.01(m, 6H; CH_(PPh,ortho)). ¹³C{¹H}-NMR (125.8 MHz, CD₂Cl₂): δ [ppm]=21.3(s, CH₃), 42.3 (dd, ¹J_(CP)=105.2 Hz, ¹J_(CP)=20.4 Hz; C_(PCS)), 64.7(br; CH_(2,allyl)), 78.3 (d, ²J_(CP)=31.8 Hz; CH_(2,allyl)), 117.7 (d,²J_(CP)=4.3 Hz; CH_(allyl)), 126.5 (s, CH_(Tol,ortho)), 127.4 (d,²J_(CP)=10.3 Hz; CH_(PPh,meta)), 128.3 (dd, ¹J_(CP)=94.0 Hz, ³J_(CP)=1.2Hz; C_(PPh,ipso)), 128.4 (dd, ¹J_(CP)=55.1 Hz, ³J_(CP)=12.4 Hz;CH_(PdPPh,ipso)), 128.5 (s, CH_(Tol,meta)), 128.5 (d, ³J_(CP)=12.8 Hz;CH_(PPh,meta)), 129.4 (d, ⁴J_(CP)=2.0 Hz; CH_(PdPPh,para)), 132.3 (d,⁴J_(CP)=3.0 Hz; CH_(PPh,para)), 135.2 (d, ²J_(CP)=10.5 Hz;CH_(PdPPh,ortho)), 136.2 (d, ²J_(CP)=10.1 Hz; CH_(PPh,ortho)), 140.9 (s,C_(Tol,para)), 144.2 (s, C_(Tol,ipso)). ³¹P{¹H}-NMR (162.0 MHz, CD₂Cl₂):δ [ppm]=9.9 (d, ²J_(PP)=67.3 Hz), 22.9 (d, ²J_(PP)=67.3 Hz).

Synthesis of the complex with the ylide-functionalizeddicyclohexylphosphane with On=PCy₃, R=R′=Cy, X=Me as prepared in Example1.D):

The phosphane Y*_(Me)PCy₂ (300 mg, 0.60 mmol) and allylpalladium(II)chloride dimer (109 mg, 0.30 mmol) were dissolved in 7 ml of toluene andstirred until a clear solution had formed. Stirring was discontinued,and the solution was stored at room temperature for 3 days. Yellowcrystals slowly formed, which were separated from the solvent, thenwashed three times with 5 ml of pentane, and dried under vacuum (230 mg,0.33 mmol, 56%; non-optimized yield).

Numbering Scheme

¹H NMR (400 MHz, CD₂Cl₂) δ=1.12-1.58 (m, 25H, CH_(2, PCy3+PCy2)), 1.62(dd, ³J_(HP)=12.4 Hz, ³J_(HP)=8.3 Hz, 3H, CH₃), 1.67-2.05 (m, 25H,CH_(2, PCy3+PCy2)), 2.10-2.24 (m, 2H, CH, _(PCy2, H1)), 2.43-3.70 (vbr,2H, CH_(2, C3H5)), 2.54-2.72 (m, 3H, CH, _(PCy3, H1)), 3.54 (dd,²J_(HH)=13.7 Hz, 3J_(HH)=8.5 Hz, 1H, CH_(2, C3H5)), 4.25-4.40 (m, 1H,CH_(2, C3H5)), 5.19-5.41 (m, 1H, CH, C_(3H5)) ppm. ¹³C {¹H} NMR (101MHz, CD₂Cl₂) δ=−2.7 (dd, ¹J_(CP)=112.1, ¹J_(CP)=46.8 Hz, P—C⁻—P), 16.4(m, CH₃), 26.9 (d, ⁴J_(CP)=1.5 Hz, CH_(2, PCy3, C4)), 27.2-27.5 (m,CH_(2, PCy2, C4)), 27.8 (d, ³J_(CP)=13.4 Hz, CH_(2, PCy2, C3)), 28.1 (d,³J_(CP)=11.3 Hz, CH_(2, Pcy3, C3)), 28.60 (d, ³J_(CP)=9.9 Hz,CH_(2, Pcy2, C3)), 28.63 (d, ²J_(CP)=2.6 Hz, CH_(2, PCy3, C2)),30.0-30.5 (m, CH_(2, PCy2, C2)), 31.2 (d, ²J_(CP)=5.2 Hz,CH_(2, Pcy2, C2)), 32.7-36.6 (m, CH, _(PCy2, C1)), 38.4-39.6 (br, CH,_(PCy3, C1)), 52.5-52.9 (m, CH_(2, C3H5)), 79.5 (d, ²J_(CP)=28.4 Hz,CH_(2, C3H5)), 114.9 (d, ²J_(CP)=4.4 Hz, CH, C_(3H5)) ppm. ³¹P {¹H} NMR(162 MHz, CD₂Cl₂) δ=20.5 (d, ²J_(PP)=63.5 Hz, PCy₂), 31.5 (d,²J_(PP)=63.5 Hz, PCy₃) ppm. CHNS: calculated: C: 61.13, H: 9.23.measured: C: 61.03, H: 9.34.

Synthesis of the complex with the ylide-functionalized phosphane withOn=PCy₃, R=R′=tBu, X=Me as prepared in Example 1.D):

The phosphane Y*_(Me)PtBu₂ (300 mg, 0.66 mmol) and allylpalladium(II)chloride dimer (115 mg, 0.32 mmol) were dissolved in 10 ml of tolueneand stirred at room temperature for 16 hours. An orange solid formed,which was filtered off, washed with 10 ml of toluene and then driedunder vacuum (265 mg, 0.42 mmol, 66%).

Numbering Scheme

¹H NMR (400 MHz, CD₂Cl₂) δ=1.02-1.56 (m, 15H, CH_(2, Cy, H2+H3+H4)),1.21 (d, ³J_(HP)=13.0 Hz, 9H, CH_(3, tBu)), 1.47 (d, ³J_(HP)=13.3 Hz,9H, CH_(3, tBu)), 1.57-1.67 (m, 3H, CH_(2, Cy, H4)), 1.68-1.89 (m, 9H,CH_(2, Cy, H3+CH3)), 1.84-1.99 (br, 3H, CH_(2, Cy, H2)), 2.08-2.20 (br,3H, CH_(2, Cy, H2)), 2.69-2.99 (br, 3H, CH, _(Cy, H1)), 2.91-3.85 (vbr,2H, CH_(2, C3H5)), 3.56 (dd, ²J_(HH)=13.5 Hz, ³J_(HH)=8.4 Hz, 1H,CH_(2, C3H5)), 4.27-4.35 (m, 1H, CH_(2, C3H5)), 5.16-5.62 (m, 1H, CH,_(C3H5)). ¹³C {¹H} NMR (101 MHz, CD₂Cl₂) δ=4.0 (dd, ¹J_(CP)=105.1 Hz,¹J_(CP)=41.3 Hz, P—C⁻—P), 18.0-19.5 (m, CH₃), 26.9 (d, ⁴J_(CP)=1.5 Hz,CH_(2, PCy3, C4)), 27.9 (d, ³J_(CP)=12.4 Hz, CH_(2, Cy, C3)), 28.4 (d,³J_(CP)=11.0 Hz, CH_(2, Cy, C3)), 29.0 (CH_(2, Cy, C2)), 29.6(CH_(2, Cy, C2)), 31.6 (CH3, tBu), 32.9 (CH3, tBu), 34.4 (d,¹J_(CP)=48.1 Hz, CH, _(Cy, C1)), 42.0-42.3 (m, C,_(tBu)), 56.3 (d,²J_(CP)=2.4 Hz, CH_(2, C3H5)), 79.1-79.7 (m, CH_(2, C3H5)), 113.7 (CH,_(C3H5)) ppm. ³¹P {¹H} NMR (162 MHz, CD₂Cl₂) δ=30.8 (d, ²J_(PP)=63.4 Hz,PCy₃), 58.0 (br, PtBu₂) ppm. CHNS: calculated: C: 58.58, H: 9.36.measured: C: 58.85, H: 9.31.

D) Palladium(0) Complexes and their Oxidative Addition Products

By way of example, the synthesis of the palladium dibenzylidene acetonecomplex with the ylide-functionalized dicyclohexylphosphane withOn=PCy₃, R=R′=Cy and X=Me as prepared in Example 1.D) is described here.Analogous palladium complexes can be synthesized with other phosphaneligands according to corresponding protocols.

A J. Young NMR tube was filled with 30 mg (59 μmol) of the phosphaneY*_(Me)PCy₂ and 34 mg (59 μmol) oftris(dibenzylideneacetone)dipalladium(0) x dibenzyl-ideneacetone. Bothsolids were suspended in 0.6 ml of deuterated THF and shaken for 30minutes. The reaction was monitored by NMR spectroscopy, and after thereaction was complete, the product was crystallized by slowly diffusingpentane into the THF solution. The product could be obtained in the formof red crystals (45 mg; 53 μmol; 89%). When an excess of phosphaneligand is used, the bisphosphane palladium(0) complex can also beisolated.

Numbering Scheme

³¹P {¹H} NMR (162 MHz, THF-d₈) δ=26.9 (d, ²J_(PP)=82.1 Hz, PCy₂), 31.6(d, ²J_(PP)=82.1 Hz, PCy₃). ¹H NMR (400 MHz, THF-d8) δ=1.02-1.86 (m,50H), 1.53 (dd, ²J_(HP)=12.6 Hz, ²J_(HP)=7.2 Hz, 3H), 1.87-2.06 (m, 2H,CH, _(PCy2, H1)), 2.09-2.32 (m, 3H, CH, _(PCy3, H1)), 5.97-6.17 (m, 2H,dba), 6.35-6.73 (m, 2H, dba), 7.10-7.31 (m, 8H, dba), 7.30-7.43 (m, 8H,dba), 7.49-7.63 (m, 4H, dba), 7.63-7.73 (m, 8H, dba), 7.73-7.79 (m, 2H,dba).

By way of example, the synthesis of a palladium(II) arylchlorido complexwith the ylide-functionalized dicyclohexylphosphane with On=PCy₃,R=R′=Cy and X=Me as prepared in Example 1.D) is described here. Otherpalladium(II) complexes can be synthesized by analogy with all otherphosphane ligands and with further aryl chlorides and bromides.

Phosphane Y*_(Me)PCy₂ (500 mg, 0.99 mmol, 1 eq.) andbis(dibenzylideneacetone)-palladium(0) (742 mg, 1.09 mmol) were stirredat RT in 10 ml of THF for 30 minutes. The solution was filtered, and 1ml of p-chlorotoluene was added, and the solution was stirred for 48hours. The dark yellow precipitate was filtered off and washed threetimes with 10 ml of THF. After drying under vacuum, the product wasobtained as a dark yellow solid (515 mg, 0.69 mmol, 70%). The complexproved to be unsoluble in all common solvents except DCM, in which itslowly decomposes, however.

Numbering Scheme

³¹P {¹H} NMR (162 MHz, CD₂Cl₂) δ=32.5 (d, ²J_(PP)=49.6 Hz), 35.1 (d,²J_(PP)=49.6 Hz) ppm. ¹H NMR (400 MHz, CD₂Cl₂) δ=0.95-2.08 (m, 52H,CH+CH_(2, PCy2+PCy3)), 1.55 (dd, ³J_(HP)=12.8 Hz, ³J_(HP)=9.4 Hz, 3H,CH₃), 2.14 (s, 3H, CH_(3,Tolyl)), 2.57 (br, 3H, CH, _(PCy3, H1)), 6.68(m, 2H, CH, _(Tolyl)), 7.08 (m, 2H, CH, _(Tolyl)) ppm.

Example 3: Transition Metal-Catalyzed Reactions withYlide-Functionalized Phosphanes

A) Gold-Catalyzed Hydroamination of Alkynes

For this purpose, the phosphane gold chloride complexes preparedaccording to the protocol of Example 2B) were dissolved in a 1:1 mixtureof alkyne and amine, and one equivalent of sodiumtetrakis[3,5-bis(trifluoromethyl)phenyl]borate was added. The mixturewas reacted under the conditions as stated in the Table below, in whichthe following conversion rates and yields were obtained. The catalysisdid not show any decrease in yield under aqueous conditions, or uponexposure of the reaction mixture to air.

Table 2: Gold(I)-Catalyzed Hydroamination of Phenylacetylene withAniline and Ylide-Functionalized Phosphanes

TABLE 2 Gold(I)-catalyzed hydroamination of phenylacetylene with anilineand ylide- functionalized phosphanes

Amount of Catalyst catalyst reaction Temp. Yield^(a) Charge L•AuCl; L =[mole %] time [h] [° C.] [%]  1 PPh₃ 5    18   RT  20^(b)  2 Y_(S)PPh₂5     0.25 RT 70  3 Y_(S)PPh₂ 1     0.25 RT 63  4 Y_(S)PPh₂ 1    6   RT99  5 Y_(S)PPh₂ 0.1  2.5 50 66  6 Y_(S)PPh₂ 0.1  5   50 82 isolated  6Y_(S)PPh₂ 0.1  14   50 94  7 Y_(S)PPh₂ 0.05  22   50 59  8 Y_(S)PPh₂0.01  22   50 28  6 —^([a]) — 24   50 —  7 Y_(S)PMe₂ 0.1  24   50 90  8Y_(S)PMe₂ 0.05  24   50 76  9 Y_(S)PCy₂ 1     0.25 RT 98 10 Y_(S)PCy₂0.1  6   RT 61 11 Y_(S)PCy₂ 0.1  22   RT 94 12 Y_(S)PCy₂ 0.1  5   50 9513 Y_(S)PCy₂ 0.05  5   50 89 14 Y_(S)PCy₂ 0.05  22   50 99 15 Y_(S)PCy₂0.025 22   50 91 16 Y_(S)PCy₂ 0.01  22   50 51 17 Y_(S)PCy₂ 0.01  48  50 74 18 Y_(S)PCy₂ 0.005 22   80 50 19 Y_(S)PCy₂ 0.005 48   80 62 20Y_(S)PCy₂ 0.1  2   50 97 ^(a)The yield was determined by NMRspectroscopy. ^(b)D. Malhotra et al. Angew. Chem. Int. Ed. 53, 4456(2014). L =

B) Gold-Catalyzed Intramolecular Addition of O—H to Alkynes

In addition to hydroamination, OH additions to alkynes can also beeffected. Thus, 4-pentynoic acid in THF reacts at room temperature with0.5 mole % Y_(s)PCy₂.AuCl and an equimolar amount of sodiumtetrakis[3,5-bis(trifluoromethyl)phenyl]-borate completely to thedesired lactone within 14 hours.

C) Pd-Catalyzed C—N Coupling Reaction

The C—N coupling reaction of amines and haloaromatics was performed withthe respective ylide-substituted phosphanes according to known synthesisprotocols. The commercially available palladacycledi-p-chlorobis[2′-(amino-N)[1,1′-biphenyl]-2-yl-C]dipalladium(II) wasused as a palladium precursor, and reacted with 1 equivalent of thephosphane ligand in THF. With the addition of sodium tert-butanolate,the amine and the bromo- or chloroaromatic were made to react.

TABLE 3 C—N coupling of phenylaniline with aryl bromides and chlorideswith the phosphane ligand Y_(Me)PCy₂.

Amount of Catalyst; catalyst Reaction Temp, Yield^(a) Charge Ligand =[mole %] Aryl halides time [h] [° C.] [%] 1 Y_(Me)PCy₂ 5   2- 16 RT 99Bromotoluene 2 Y_(Me)PCy₂ 5   4- 16 RT 40 Chlorobenzo- nitrile 3Y_(Me)PCy₂ 5   4- 16  60 95 Chlorobenzo- nitrile 4 Y_(Me)PCy₂ 2.5 4- 18100 17 Chlorotoluene 5 Y_(Me)PCy₂ 2.5 4- 48 100 39 Chlorotoluene ^(a)Theyield was determined by NMR spectroscopy. “Pd” =

In a glove box, 1.5-2.0 equivalents of potassium tert-butanolate (orsodium tert-butanolate) was added to a screw-cap vessel. Outside theglove box, the aryl chloride (0.9-1.2 mmol) and 1.1 eq. of an amine aswell as 2 ml of solvent were added. In a second vessel, a catalystsolution (see below) was prepared, and the corresponding amount ofcatalyst was added to the reaction. The reaction mixture was stirred atroom temperature. After the period as stated in the Table, the reactionwas quenched with water, and the product was isolated by columnchromatography. Alternatively, yields were determined by NMRspectroscopy. α,α,α-trifluorotoluene in the case ofp-fluorochlorobenzene, and 1,3,5-trimethoxybenzene in the case of thefluorine-free chloroaromatics, were used as internal standards. For adetermination after defined reaction times, small amounts of thereaction solution were withdrawn and quenched with a little water. Theorganic phase was taken off, filtered, and the solvent was removed. Theresidue was dissolved in CDCl₃, and the conversion was determined bymeans of the ratio of product peak to internal standard.

In an analogous way, aryl bromides can be employed in the couplingreactions.

Catalyst Preparation:

-   -   1) The ligand L1 (or L2-L6) and an equimolar amount of        bis(di-benzylideneacetone)palladium(0) (or Pd(OAc)₂) were        dissolved in THF (or dioxane, or toluene; see Table), and        stirred at room temperature for 30 minutes. An appropriate        amount of the solution was subsequently added to the reaction        vessel.    -   2) The precatalysts P1, P2, P4-P8 were dissolved in THF and        stirred at room temperature for 30 minutes. An appropriate        amount of the solution was subsequently added to the reaction        vessel.    -   3) The corresponding amount of precatalyst P3 was directly added        to the reaction solution.

R (Pre)catalyst Base Solvent Yield [%]^([a]) Me L1•Pd₂dba₃ KOtBu THF 95Me L1•Pd₂dba₃ NaOtBu THF 52 Me L1•Pd₂dba₃ KOtBu dioxane 99 F L1•Pd₂dba₃KOtBu THF 83 F L1•Pd₂dba₃ NaOtBu THF 45 F L1•Pd₂dba₃ KOtBu dioxane 88 FL1•Pd(OAc)₂ KOtBu THF 87 F P4 or P5 or P6 or KOtBu THF <1 P7 or P8 F L3or L4 or L5 KOtBu THF <1 with Pd₂dba₃ F L6•Pd(OAc)₂ ^([b]) NaOtButoluene 10 (84)^([c]) F L1•Pd(OAc)₂ ^([b]) NaOtBu toluene 78 (88)^([c])^([a])Yields were determined by NMR spectroscopy. ^([b])1 mole % ofligand. ^([c])After 19 h.

Application of Different Aryl Chlorides with P*_(Me)PCy₂ (L1) as Ligands

Yields are Isolated Yields.

Application of Different Amines and Catalyst Systems Based onP*_(Me)PCy₂ (L1) and P*_(Me)PtBu₂ (L2)

Amine 1 h 3 h 6 h 24 h n-Butylamine 41% 49% 51% 60% Piperidine >99%  — —— iso-Propylamine 15% 20% 22% 27% tert-Butylamine 28% 83% >99%  —Diethylamine 48% 60% 67% 67% N-Methylaniline >99%  — — —

Amine 1 h 3 h 6 h 24 h n-Butylamine 53% 77% 92% >99%  Piperidine 10% 23%49% 63% iso-Propylamine 17% 27% 30% 43% tert-Butylamine <1%  3%  5%  9%Diethylamine <1%  3%  5% 23% N-Methylaniline  6% 10% 15% 57%

Amine 1 h 3 h 6 h 24 h n-Butylamine 37% 44% 44% 51% Piperidine >99%  — —— iso-Propylamine 15% 17% 20% 23% tert-Butylamine 16% 21% 31% 34%Diethylamine 50% 78% 93% 98% N-Methylaniline >99%  — — —

Amine 1 h 3 h 6 h 24 h n-Butylamine >99% — — — Piperidine >99% — — —iso-Propylamine  54% 54% 57% 61% tert-Butylamine  18% 18% 19% 20%Diethylamine  46% 54% 60% 64% N-Methylaniline >99% — — —

AminE 1 h 3 h 6 h 24 h n-Butylamine 44% 61% 62% 64% Piperidine >99%  — —— iso-Propylamine 13% 19% 20% 25% tert-Butylamine 37% >99%  — —Diethylamine 61% 63% 63% 68% N-Methylaniline >99%  — — —

D) Pd-Catalyzed C—C Coupling Reaction

The C—C coupling reaction of boronic acid and haloaromatics wasperformed with the respective ylide-substituted phosphanes according toknown synthesis protocols. The commercially available palladacycledi-p-chlorobis[2′-(amino-N)[1,1′-biphenyl]-2-yl-C]dipalladium(II) wasused as a palladium precursor, and reacted with 1 equivalent of thephosphane ligand in THF. With the addition of an aqueous solution ofpotassium phosphate, the amine and the bromo- or chloroaromatic weremade to react.

TABLE 4 C—C coupling of phenylboronic acid with aryl bromides andchlorides with the phosphene ligands Y_(Me)PCy₂ and YSPCy_(2.)

Amount of Catalist; catalyst Reaction Temp. Yield^(a) Charge Ligand =[mole %] Aryl halides time [h] [° C.] [%] 1 Y_(S)PCy₂ 2 2-Bromotoluene24 RT 60 2 Y_(Me)PCy₂ 2 2-Bromotoluene 24 RT 16 3 Y_(Me)PCy₂ 52-Bromotoluene 24 60 99 4 Y_(Me)PCy₂ 2 4-Bromo- 48 RT 84 acetophenone 5Y_(Me)PCy₂ 5 4-Chlorotoluene 24 60 27 6 Y_(Me)PCy₂ 5 4-Chloro- 24 60 95benzonitrile ^(a)The yield was determined by NMR spectroscopy. “Pd” =

Heck Reaction with YPhos

In a glove box, potassium carbonate was added to a Schlenk vessel with astirring rod. 2 ml of dry DMF (dimethylformamide), aryl halide (1.1mmol) and olefin (2.1 mmol) were added.

A stock solution of catalyst and ligand was prepared by mixing 0.2 mmolpalladium acetate Pd(OAc)₂ and 0.2 mmol YPhos in a Schlenk vessel. 1 mlof dry THF (tetrahydrofuran) was added, the mixture was stirred for 30min, and 0.1 ml of the thus obtained solution was added to the reactionmixture, and all was stirred at 140° C. for 3 hours. Yields weredetermined by F-NMR analysis with α,α,α-trifluorotoluene as internalstandard.

YPhos:

For the project on which this application is based, grants of theEuropean Research Council (ERC) were provided within the scope of theprogramme of the European Union for Research and Innovation “Horizon2020” (Grant Agreement No. 677749).

The invention claimed is:
 1. Metal complexes having phosphane ligands offormula (I)

wherein On is a phosphonium group —P(R³R⁴R⁵), in which R³, R⁴ and R⁵ areindependently selected from the group consisting of C₁₋₆ alkyl groups,C₄₋₁₀ cycloalkyl groups, C₆₋₁₀ aryl groups, X is selected from the groupconsisting of linear, branched-chain or cyclic C₁₋₆ alkyl groups, C₆₋₁₀aryl groups, mono- or polyunsaturated linear, branched-chain or cyclicC₂₋₆ alkenyl groups, a trialkylsilyl (—SiR³R⁴R⁵), arylsulfonyl group,and R¹ and R² are C₆₋₁₀ aryl groups or C₁₋₆ alkyl and cycloalkyl groups,with the proviso that ligands where R¹ and R² are phenyl, On istriphenylphosphine (PPh₃) and X is phenyl or methyl are excluded.
 2. Themetal complexes according to claim 1, wherein R³, R⁴ and R⁵ areindependently selected from the group consisting of methyl, ethyl,butyl, cyclohexyl, phenyl, and combinations thereof.
 3. The metalcomplexes according to claim 1, wherein X is selected from the groupconsisting of methyl, ethyl, cyclohexyl, phenyl, p-tolyl,trimethylsilyl, p-tolylsulfonyl, or combinations thereof.
 4. The metalcomplexes according to claim 1, wherein said complex is a palladiumallyl complex having the following structure (V)

wherein X′ is an anion, Y is On-C—X, R³³, R³⁴ and R³⁵ are independentlyselected from H, alkyl, aryl and heteroaryl groups that may beunsubstituted or substituted with functional groups; or at least two ofR³³, R³⁴ and R³⁵ form a carbocyclic ring with 5 to 14 carbon atoms, Arrepresents a substituted or unsubstituted aryl group.
 5. The metalcomplexes according to claim 4, wherein R³³, R³⁴ and R³⁵ areindependently selected from linear, branched-chain or cyclic C₁₋₁₀ alkylgroups, the aryl groups are selected from C₆₋₁₄ aryl groups, the alkenylgroups are selected from mono- or polyunsaturated linear, branched-chainor cyclic C₂₋₁₀ alkenyl groups, and the heteroaryl groups are selectedfrom C₆₋₁₄ heteroaryl groups, wherein all of the groups mentioned areoptionally substituted with functional groups; or at least two of R³³,R³⁴ and R³⁵ form a carbocyclic ring that is a C₄₋₁₀ cycloalkyl group, ora C₆₋₁₄ aryl group, optionally substituted with one or more functionalgroups; and Ar are selected from C₆₋₁₄ aryl groups and the heteroarylgroups are selected from C₆₋₁₄ heteroaryl groups, wherein all of thegroups mentioned are optionally substituted with functional groups; andthe functional groups are selected from C₁₋₆ alkyl groups, C₆₋₁₀ aryl,halogen, hydroxy, cyano, alkoxy, amino, or mercapto.
 6. The metalcomplexes of claim 1, wherein the metal of the metal complex is selectedfrom the group consisting of copper, silver, gold, platinum, palladium,nickel, and combinations thereof.
 7. A process for performing a couplingreaction containing the steps of providing a reaction mixture containingat least a substrate, coupling partner, and the metal complex accordingto claim 1; and reacting said substrate with said coupling partner inthe presence of the metal complex or its derivative to form a couplingproduct.
 8. The process according to claim 7, wherein the metal of saidmetal complex is a precious metal or a transition metal.
 9. The processaccording to claim 7, wherein the metal of said metal complex is a metalof group 10 or 11 of the Periodic Table of the elements.
 10. The processaccording to claim 7, wherein the metal of said metal complex isselected from the group consisting of copper, silver, gold, platinum,palladium, nickel, and combinations thereof.